Abstract
Using a question and answer format we describe important aspects of using genomic technologies in cancer research. The main challenges are not managing the mass of data, but rather the design, analysis, and accurate reporting of studies that result in increased biological knowledge and medical utility. Many analysis issues address the use of expression microarrays but are also applicable to other whole genome assays. Microarray-based clinical investigations have generated both unrealistic hype and excessive skepticism. Genomic technologies are tremendously powerful and will play instrumental roles in elucidating the mechanisms of oncogenesis and in bringing on an era of predictive medicine in which treatments are tailored to individual tumors. Achieving these goals involves challenges in rethinking many paradigms for the conduct of basic and clinical cancer research and for the organization of interdisciplinary collaboration.