New advances in microarrays: finding the genes causally involved in disease.

Much progress has been made in the technologies available to assess global alterations in mRNA levels in clinical research samples. Although such transcript profiling can provide a powerful research tool, the broad range of options can be bewildering for the inexperienced investigator, and more often than not the limitations and pitfalls of this approach are not fully appreciated. It is important to recognize that the major goal of transcript profiling experiments can be to identify novel therapeutic targets or delineate complex patterns of gene expression that provide a potentially pathognomonic phenotype. Microarrays are therefore potentially powerful tools to address the need for high-throughput analysis techniques, but a careful postanalysis follow-up and validation of microarray experiments will be needed soon (1). A projected decrease in cost and complexity may facilitate increased availability of this technology in the physician's office, and future applications may then allow tailoring of clinical diagnosis and targeted therapeutic strategies.