A library of gene expression signatures to illuminate normal and pathological lymphoid biology

Follicular lymphomas with and without translocation t(14;18) differ in gene expression profiles and genetic alterations

Follicular lymphoma (FL) is genetically characterized by the presence of the t(14;18)(q32;q21) chromosomal translocation in approximately 90% of cases. In contrast to FL carrying the t(14;18), their t(14;18)-negative counterparts are less well studied about their immunohistochemical, genetic, molecular, and clinical features. Within a previously published series of 184 FLs grades 1 to 3A with available gene expression data, we identified 17 FLs lacking the t(14;18). Comparative genomic hybridization and high-resolution single nucleotide polymorphism (SNP) array profiling showed that gains/amplifications of the BCL2 gene locus in 18q were restricted to the t(14;18)-positive FL subgroup. A comparison of gene expression profiles showed an enrichment of germinal center B cell-associated signatures in t(14;18)-positive FL, whereas activated B cell-like, NFkappaB, proliferation, and bystander cell signatures were enriched in t(14;18)-negative FL. These findings were confirmed by immunohistochemistry in an independent validation series of 84 FLs, in which 32% of t(14;18)-negative FLs showed weak or absent CD10 expression and 91% an increased Ki67 proliferation rate. Although overall survival did not differ between FL with and without t(14;18), our findings suggest distinct molecular features of t(14;18)-negative FL.

IRF4: Immunity. Malignancy! Therapy?

IRF4, a member of the Interferon Regulatory Factor (IRF) family of transcription factors, is expressed in cells of the immune system, where it transduces signals from various receptors to activate or repress gene expression. IRF4 expression is a key regulator of several steps in lymphoid-, myeloid-, and dendritic-cell differentiation, including the differentiation of mature B cells into antibody-secreting plasma cells. IRF4 expression is also associated with many lymphoid malignancies, with recent evidence pointing to an essential role in multiple myeloma, a malignancy of plasma cells. Interference with IRF4 expression is lethal to multiple myeloma cells, irrespective of their genetic etiology, making IRF4 an "Achilles' heel" that may be exploited therapeutically.

A20 takes on tumors: tumor suppression by an ubiquitin-editing enzyme

Many B cell cancers are characterized in part by the dysregulation of the NF-kappaB signaling pathway. A new study identifies somatic mutations in TNFAIP3, the gene encoding the NF-kappaB inhibitor A20, in Hodgkin lymphomas and primary mediastinal lymphomas. These data reveal the role of A20 as a tumor suppressor protein.

Depletion of guanine nucleotides leads to the Mdm2-dependent proteasomal degradation of nucleostemin

Nucleostemin is a positive regulator of cell proliferation and is highly expressed in a variety of stem cells, tumors, and tumor cell lines. The protein shuttles between the nucleolus and the nucleus in a GTP-dependent fashion. Selective depletion of intracellular guanine nucleotides by AVN-944, an inhibitor of the de novo purine synthetic enzyme, IMP dehydrogenase, leads to the rapid disappearance of nucleostemin protein in tumor cell lines, an effect that does not occur with two other nucleolar proteins, nucleophosmin or nucleolin. Endogenous nucleostemin protein is completely stabilized by MG132, an inhibitor of the 26S proteasome, as are the levels of expressed enhanced green fluorescent protein-tagged nucleostemin, both wild-type protein and protein containing mutations at the G(1) GTP binding site. Nutlin-3a, a small molecule that disrupts the binding of the E3 ubiquitin ligase, Mdm2, to p53, stabilizes nucleostemin protein in the face of guanine nucleotide depletion, as does siRNA-mediated knockdown of Mdm2 expression and overexpression of a dominant-negative form of Mdm2. Neither Doxorubicin nor Actinomycin D, which cause the release of nucleostemin from the nucleolus, results in nucleostemin degradation. We conclude that nucleostemin is a target for Mdm2-mediated ubiquitination and degradation when not bound to GTP. Because this effect does not occur with other chemotherapeutic agents, the induction of nucleostemin protein degradation in tumor cells by IMP dehydrogenase inhibition or by other small molecules that disrupt GTP binding may offer a new approach to the treatment of certain neoplastic diseases.

TCL1A expression delineates biological and clinical variability in B-cell lymphoma

The assembly of a collection of gene-expression signatures of the major types of B-cell non-Hodgkin's lymphoma has identified increased T-cell leukemia/lymphoma 1A (TCL1) expression in multiple lymphoma types and cases, and has enabled the investigation of the functional and clinical importance of TCL1 expression. Specifically, Burkitt's lymphoma cases show a homogeneously strong expression of TCL1, whereas diffuse large B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, chronic lymphocytic leukemia, nodal marginal zone lymphoma, and splenic marginal zone lymphoma display a striking variability in the intensity of TCL1 staining. This was validated in two independent series. A Gene-Set Enrichment Analysis of the genes correlated with TCL1A expression found that variation in the level of expression of TCL1A was significantly associated with some of the most important gene signatures recognizing B-cell lymphoma pathogenesis and heterogeneity, such as germinal center, B-cell receptor, NF-kappaB (and its target genes), death, MAP kinases, TNFR1, TOLL, and IL1R. Additionally, TCL1 expression was correlated with shorter time to treatment in chronic lymphocytic leukemia cases and shorter lymphoma-specific survival in mantle cell lymphoma series, thus indicating the clinical and biological significance of TCL1 expression, and suggesting TCL1A as a potential therapeutic target.

Expression pattern of XBP1(S) in human B-cell lymphomas

The transcription factor XBP1 (X-box-binding protein 1) is essential for plasma cell (PC) differentiation and immunoglobulin secretion. XBP1 is widely expressed, but its activity is precisely controlled by mRNA splicing in response to endoplasmic reticulum (ER) stress. It is the active form of XBP1, XBP1(S), which is required for PC differentiation. The relationship between XBP1(S) expression and PC differentiation in human tissue and its expression in hematologic malignancies has eluded assessment. With a novel antibody, we now define XBP1(S) expression in a large series of normal and neoplastic lymphoid tissues. We establish that XBP1(S) provides a specific marker of advanced plasma differentiation and in lymphoid malignancies is restricted to PC-derived neoplasms and plasmablastic diffuse large B-cell lymphomas. XBP1(S) expression delineates heterogeneity amongst plasmablastic diffuse large B-cell lymphomas, identifying a distinct tumor sub-group. Furthermore, our results establish a direct and practical means of assessing ER stress in human tumors.

Differential gene expression of peripheral blood mononuclear cells from rheumatoid arthritis patients may discriminate immunogenetic, pathogenic and treatment features

This study aimed to evaluate the association between the differential gene expression profiling of peripheral blood mononuclear cells of rheumatoid arthritis patients with their immunogenetic (human leucocyte antigen shared-epitope, HLA-SE), autoimmune response [anti-cyclic citrullinated peptide (CCP) antibodies], disease activity score (DAS-28) and treatment (disease-modifying antirheumatic drugs and tumour necrosis factor blocker) features. Total RNA samples were copied into Cy3-labelled complementary DNA probes, hybridized onto a glass slide microarray containing 4500 human IMAGE complementary DNA target sequences. The Cy3-monocolour microarray images from patients were quantified and normalized. Analysis of the data using the significance analysis of microarrays algorithm together with a Venn diagram allowed the identification of shared and of exclusively modulated genes, according to patient features. Thirteen genes were exclusively associated with the presence of HLA-SE alleles, whose major biological function was related to signal transduction, phosphorylation and apoptosis. Ninety-one genes were associated with disease activity, being involved in signal transduction, apoptosis, response to stress and DNA damage. One hundred and one genes were associated with the presence of anti-CCP antibodies, being involved in signal transduction, cell proliferation and apoptosis. Twenty-eight genes were associated with tumour necrosis factor blocker treatment, being involved in intracellular signalling cascade, phosphorylation and protein transport. Some of these genes had been previously associated with rheumatoid arthritis pathogenesis, whereas others were unveiled for future research.

Stromal gene signatures in large-B-cell lymphomas

BACKGROUND

The addition of rituximab to combination chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), or R-CHOP, has significantly improved the survival of patients with diffuse large-B-cell lymphoma. Whether gene-expression signatures correlate with survival after treatment of diffuse large-B-cell lymphoma is unclear.

METHODS

We profiled gene expression in pretreatment biopsy specimens from 181 patients with diffuse large-B-cell lymphoma who received CHOP and 233 patients with this disease who received R-CHOP. A multivariate gene-expression-based survival-predictor model derived from a training group was tested in a validation group.

RESULTS

A multivariate model created from three gene-expression signatures--termed "germinal-center B-cell," "stromal-1," and "stromal-2"--predicted survival both in patients who received CHOP and patients who received R-CHOP. The prognostically favorable stromal-1 signature reflected extracellular-matrix deposition and histiocytic infiltration. By contrast, the prognostically unfavorable stromal-2 signature reflected tumor blood-vessel density.

CONCLUSIONS

Survival after treatment of diffuse large-B-cell lymphoma is influenced by differences in immune cells, fibrosis, and angiogenesis in the tumor microenvironment.

A distinctive subtype of t(14;18)-negative nodal follicular non-Hodgkin lymphoma characterized by a predominantly diffuse growth pattern and deletions in the chromosomal region 1p36

Follicular lymphoma (FL) is a morphologically and genetically well-characterized B-cell non-Hodgkin lymphoma that can show predominantly follicular, combined follicular and diffuse, or predominantly diffuse growth patterns. Although approximately 85% of FLs harbor the translocation t(14;18)(q32;q21) and consistently display a follicular growth pattern, predominantly diffuse FLs are less well characterized on the phenotypical, molecular, and clinical level. We studied 35 predominantly diffuse FL by immunohistochemistry, classical chromosome banding analysis, fluorescence in situ hybridization (FISH), and gene expression profiling. A total of 28 of 29 analyzable cases lacked t(14;18), and 27 of 29 cases revealed a unifying chromosomal aberration, a deletion in 1p36. Morphologically, 12 FLs were grade 1 and 23 were grade 2, and the immunophenotype with frequent expression of CD10, BCL6, and CD23 was in line with a germinal center B-cell phenotype. The gene expression profiles of 4 predominantly diffuse FLs fell into the spectrum of typical FL, with a unique enrichment of specific gene signatures. Remarkably, patients with diffuse FL frequently presented with low clinical stage and large but localized inguinal tumors. These results suggest that predominantly diffuse FL represent a distinct subtype of t(14;18)-negative nodal FL with a unifying genetic alteration (deletion of 1p36) and characteristic clinical features.

Regulation and functions of Blimp-1 in T and B lymphocytes

B lymphocyte-induced maturation protein-1 (Blimp-1), discovered 16 years ago as a transcriptional repressor of the IFNbeta promoter, plays fundamentally important roles in many cell lineages and in early development. This review focuses on Blimp-1 in lymphocytes. In the B cell lineage, Blimp-1 is required for development of immunoglobulin-secreting cells and for maintenance of long-lived plasma cells (LLPCs). Direct targets of Blimp-1 and the transcriptional cascades Blimp-1 initiates to trigger plasmacytic differentiation are described. Blimp-1 also affects the homeostasis and function of CD4(+), CD8(+), and regulatory CD4(+) T cells, and Blimp-1 levels are highest in antigen-experienced T cells. Blimp-1 attenuates T cell proliferation and survival and modulates differentiation. Roles for Blimp-1 in Th1/Th2 specification, regulatory T cell function, and CD8 differentiation and function are under investigation. Signals that induce Blimp-1 in B cells include Toll-like receptor ligands and cytokines; in T cells, T cell receptors and cytokines induce Blimp-1. In spite of some commonalities, different targets and regulators of Blimp-1 in B and T cells suggest intriguing evolutionary divergence of this regulatory machinery.

The biochemistry of somatic hypermutation

Affinity maturation of the humoral response is mediated by somatic hypermutation of the immunoglobulin (Ig) genes and selection of higher-affinity B cell clones. Activation-induced cytidine deaminase (AID) is the first of a complex series of proteins that introduce these point mutations into variable regions of the Ig genes. AID deaminates deoxycytidine residues in single-stranded DNA to deoxyuridines, which are then processed by DNA replication, base excision repair (BER), or mismatch repair (MMR). In germinal center B cells, MMR, BER, and other factors are diverted from their normal roles in preserving genomic integrity to increase diversity within the Ig locus. Both AID and these components of an emerging error-prone mutasome are regulated on many levels by complex mechanisms that are only beginning to be elucidated.

Efficacy, pharmacokinetics, tisssue distribution, and metabolism of the Myc-Max disruptor, 10058-F4 [Z,E]-5-[4-ethylbenzylidine]-2-thioxothiazolidin-4-one, in mice

OBJECTIVES

c-Myc is commonly activated in many human tumors and is functionally important in cellular proliferation, differentiation, apoptosis and cell cycle progression. The activity of c-Myc requires noncovalent interaction with its client protein Max. In vitro studies indicate the thioxothiazolidinone, 10058-F4, inhibits c-Myc/Max dimerization. In this study, we report the efficacy, pharmacokinetics and metabolism of this novel protein-protein disruptor in mice.

METHODS

SCID mice bearing DU145 or PC-3 human prostate cancer xenografts were treated with either 20 or 30 mg/kg 10058-F4 on a qdx5 schedule for 2 weeks for efficacy studies. For pharmacokinetics and metabolism studies, mice bearing PC-3 or DU145 xenografts were treated with 20 mg/kg of 10058-F4 i.v. Plasma and tissues were collected 5-1440 min after dosing. The concentration of 10058-F4 in plasma and tissues was determined by HPLC, and metabolites were characterized by LC-MS/MS.

RESULTS

Following a single iv dose, peak plasma 10058-F4 concentrations of approximately 300 muM were seen at 5 min and declined to below the detection limit at 360 min. Plasma concentration versus time data were best approximated by a two-compartment, open, linear model. The highest tissue concentrations of 10058-F4 were found in fat, lung, liver, and kidney. Peak tumor concentrations of 10058-F4 were at least tenfold lower than peak plasma concentrations. Eight metabolites of 10058-F4 were identified in plasma, liver, and kidney. The terminal half-life of 10058-F4 was approximately 1 h, and the volume of distribution was >200 ml/kg. No significant inhibition of tumor growth was seen after i.v. treatment of mice with either 20 or 30 mg/kg 10058-F4.

CONCLUSION

The lack of significant antitumor activity of 10058-F4 in tumor-bearing mice may have resulted from its rapid metabolism and low concentration in tumors.

Cooperative signaling through the signal transducer and activator of transcription 3 and nuclear factor-{kappa}B pathways in subtypes of diffuse large B-cell lymphoma

The activated B cell-like (ABC) subgroup of diffuse large B-cell lymphoma (DLBCL) is characterized by constitutive activation of the nuclear factor-kappaB (NF-kappaB) pathway. In this study, we showed that the NF-kappaB pathway induced the expression of the cytokines interleukin (IL)-6 and IL-10 in ABC DLBCL cell lines, which also have high levels of total and phosphorylated signal transducer and activator of transcription (STAT) 3 protein, suggesting autocrine signaling. Using RNA interference for STAT3, we defined a gene expression signature of IL-6 and IL-10 signaling through STAT3. Based on this signature, we constructed a molecular predictor of STAT3 signaling that defined a subset of ABC DLBCL tumors with high expression of STAT3, IL-6, and/or IL-10 and their downstream targets. Although the STAT3-high and STAT3-low subsets had equivalent expression of genes that distinguish ABC DLBCL from germinal center B cell-like DLBCL, STAT3-high ABC DLBCLs had higher expression of signatures that reflected NF-kappaB activity, proliferation, and glycolysis. A small-molecule inhibitor of Janus kinase signaling, which blocked STAT3 signature expression, was toxic only for ABC DLBCL lines and synergized with an inhibitor of NF-kappaB signaling. These findings suggest that the biological interplay between the STAT3 and NF-kappaB pathways may be exploited for the treatments of a subset of ABC DLBCLs.

The utility of PAX5 immunohistochemistry in the diagnosis of undifferentiated malignant neoplasms

PAX5 is a B-cell transcription factor whose expression at the protein level is reliably detected by immunohistochemistry in routine biopsies. The purpose of this study was to investigate whether PAX5 immunohistochemistry has diagnostic benefit as a B-cell marker in the work-up of undifferentiated malignant neoplasms. Twenty-five cases previously diagnosed as undifferentiated malignant neoplasms were selected. In addition, 59 hematolymphoid and 884 non-hematolymphoid malignancies were studied such that the specificity of PAX5 immunohistochemistry could be addressed. Two of the 25 (8%) undifferentiated neoplasms showed diffuse staining for PAX5, which indicated a B-cell derivation for these neoplasms that was not appreciated at the time of initial diagnosis. PAX5 staining was detected in the vast majority of hematolymphoid tumors of B-cell derivation but only in 5 of 884 (less than 1%) non-hematolymphoid tumors. Our results further show that PAX5 may be the only detectable marker of B lineage in lymphomas that lack or show equivocal CD45RB and CD20 expression. We conclude that the addition of PAX5 to a panel of immunohistologic markers used in the interrogation of undifferentiated neoplasms is of diagnostic benefit. Its expression can also facilitate the diagnosis of classical and nodular lymphocyte-predominant Hodgkin lymphoma with atypical morphologic and immunohistologic features. Lastly, we have shown that the lack of its expression at the protein level in many epithelial and mesenchymal neoplasms renders PAX5 expression an extremely specific marker of the B lineage.

Genome wide transcriptional analysis of resting and IL2 activated human natural killer cells: gene expression signatures indicative of novel molecular signaling pathways

BACKGROUND

Human natural killer (NK) cells are the key contributors of innate immune response and the effector functions of these cells are enhanced by cytokines such as interleukine 2 (IL2). We utilized genome-wide transcriptional profiling to identify gene expression signatures and pathways in resting and IL2 activated NK cell isolated from peripheral blood of healthy donors.

RESULTS

Gene expression profiling of resting NK cells showed high expression of a number of cytotoxic factors, cytokines, chemokines and inhibitory and activating surface NK receptors. Resting NK cells expressed many genes associated with cellular quiescence and also appeared to have an active TGFbeta (TGFB1) signaling pathway. IL2 stimulation induced rapid downregulation of quiescence associated genes and upregulation of genes associated with cell cycle progression and proliferation. Numerous genes that may enhance immune function and responsiveness including activating receptors (DNAM1, KLRC1 and KLRC3), death receptor ligand (TNFSF6 (FASL) and TRAIL), chemokine receptors (CX3CR1, CCR5 and CCR7), interleukin receptors (IL2RG, IL18RAB and IL27RA) and members of secretory pathways (DEGS1, FKBP11, SSR3, SEC61G and SLC3A2) were upregulated. The expression profile suggested PI3K/AKT activation and NF-kappaB activation through multiple pathways (TLR/IL1R, TNF receptor induced and TCR-like possibly involving BCL10). Activation of NFAT signaling was supported by increased expression of many pathway members and downstream target genes. The transcription factor GATA3 was expressed in resting cells while T-BET was upregulated on activation concurrent with the change in cytokine expression profile. The importance of NK cells in innate immune response was also reflected by late increased expression of inflammatory chemotactic factors and receptors and molecules involved in adhesion and lymphocyte trafficking or migration.

CONCLUSION

This analysis allowed us to identify genes implicated in cellular quiescence and the cytokines and cytotoxic factors ready for immediate immune response. It also allowed us to observe the sequential immunostimulatory effects of IL2 on NK cells improving our understanding of the biology and molecular mediators behind NK cell activation.

Predicting the outcome in non-Hodgkin lymphoma with molecular markers

The World Health Organization classification divides non-Hodgkin lymphomas into B-cell, T-cell and natural killer-cell lymphomas. They are heterogeneous in epidemiology, histopathology and outcome. Clinical prognostic indices rely only on patient factors and staging. Molecular prognostic markers reflect the intrinsic lymphoma biology, measure tumour load and may provide novel therapeutic targets. Lymphomagenesis involves mutations, deletions or dysregulations of genes critical in the control of cell cycle and apoptosis, which are in turn prognostically important. Genome-wide gene expression profiling, either by allowing lymphomas to be classified according to different stages of lymphoid maturation, or by defining specific gene expression signatures, is also of prognostic significance. In lymphomas where viral infections of the neoplastic cells occur, quantification of viral copies is a surrogate marker for tumour load and hence prognosis. Molecular markers together with patient and clinicopathological features will provide more accurate prognostic models for risk stratification, in order to improve treatment outcome.

The Biology of the Germinal Center

The immune system requires the production of high affinity antibodies of different subclasses to accomplish its many effector functions. Specific steps in B-cell ontogeny that occur within germinal centers of secondary lymphoid organs create much of the diversity in the immune system. This process also provides the raw material for the genesis of B-cell lymphomas as misdirection of the molecular machinery that regulate these steps can cause chromosomal translocations, prevent apoptosis and promote proliferation of abnormal clones. Many recent avenues of investigation have elucidated that the germinal center is a dynamic microenvironment where B-cells undergo repeated rounds of mutation and selection. Gene expression studies have further shown that malignancies derived from germinal center B-cells elaborate specific gene expression signatures that derive from neoplastic cells as well as elements of the host response such as T-cells and macrophages. This review will examine the current understanding of B-cell development in the germinal center and the key molecules involved in this process. Interactions between lymphoma cells and their cellular partners and models in the growth and development of follicular lymphoma will be presented.

The Biology of the Germinal Center

The immune system requires the production of high affinity antibodies of different subclasses to accomplish its many effector functions. Specific steps in B-cell ontogeny that occur within germinal centers of secondary lymphoid organs create much of the diversity in the immune system. This process also provides the raw material for the genesis of B-cell lymphomas as misdirection of the molecular machinery that regulate these steps can cause chromosomal translocations, prevent apoptosis and promote proliferation of abnormal clones. Many recent avenues of investigation have elucidated that the germinal center is a dynamic microenvironment where B-cells undergo repeated rounds of mutation and selection. Gene expression studies have further shown that malignancies derived from germinal center B-cells elaborate specific gene expression signatures that derive from neoplastic cells as well as elements of the host response such as T-cells and macrophages. This review will examine the current understanding of B-cell development in the germinal center and the key molecules involved in this process. Interactions between lymphoma cells and their cellular partners and models in the growth and development of follicular lymphoma will be presented.

Genomics of brain and blood: progress and pitfalls

Gene expression profiles in brain and blood of animals and humans can be useful for diagnosis, prognosis, and treatment of epilepsy. This article reviews recent progress and prospects for the future.

Genome-scale Assessment of Molecular Pathology in Systemic Autoimmune Diseases using Microarray Technology: A Potential Breakthrough Diagnostic and Individualized Therapy-design Tool

Systemic autoimmune rheumatic diseases are of complex aetiology, characterized by an intricate interplay of various factors. A myriad of genes lies behind the heterogeneous manifestations of these diseases, and the overexpression and repression of particular genes form a specific gene-expression profile (genetic fingerprints) that is characteristic to the given disease phenotype. Besides the description of various cell types by using gene-expression profiling, the data should be directly applicable to the design of individual therapeutic protocols for patients suffering from various autoimmune diseases. In this review, we summarize the gene-expression profile, various genetic signatures of different autoimmune diseases and give an overview on the possible interpretations of the data. The application of recent breakthroughs in high-throughput molecular profiling technologies, such as microarray technology has been the basis for a revolution in biomedical research, as well as diagnostics and pharmaceutical development. It is easy to envision a day when personalized medicine, which is the diagnosis and treatment of a given patient with agents and procedures tailored to that patient's genetics, physiology and pathology, will become the standard of care.

The c-Myc target gene network

For more than a decade, numerous studies have suggested that the c-Myc oncogenic protein is likely to broadly influence the composition of the transcriptome. However, the evidence required to support this notion was made available only recently, much to the anticipation of an eagerly awaiting field. In the past 5 years, many high-throughput screens based on microarray gene expression profiling, serial analysis of gene expression (SAGE), chromatin immunoprecipitation (ChIP) followed by genomic array analysis, and Myc-methylase chimeric proteins have generated a wealth of information regarding Myc responsive and target genes. From these studies, the c-Myc target gene network is estimated to comprise about 15% of all genes from flies to humans. Both genomic and functional analyses of c-Myc targets suggest that while c-Myc behaves as a global regulator of transcription, groups of genes involved in cell cycle regulation, metabolism, ribosome biogenesis, protein synthesis, and mitochondrial function are over-represented in the c-Myc target gene network. c-Myc also consistently represses genes involved in cell growth arrest and cell adhesion. The overexpression of c-Myc predisposes cells to apoptosis under nutrient or growth factor deprivation conditions, although the critical sets of genes involved remain elusive. Despite tremendous advances, the downstream target genes that distinguish between physiologic and tumorigenic functions of c-Myc remain to be delineated.

Gene expression microarrays: glimpses of the immunological genome

Successful microarray experimentation can generate enormous amounts of data, potentially very rich but also very unwieldy. Bold outlooks and new methods for data analysis and presentation should yield additional insight into the complexities of the immune system.