Victor E. Velculescu was working as a graduate student at Johns Hopkins University with Kenneth Kinzler in the mid-1990s when he hit a technological roadblock. "We knew there were molecular differences between cancer cells and normal cells," says Velculescu, "but we just didn't have a good way of examining what those differences were, except a few genes at a time."
When Velculescu went to invent a novel approach of his own, he came up with an unbiased gene-expression profiling technique called serial analysis of gene expression (SAGE). "The approach provided a way to look at the expression of thousands of genes at one time, and identifying the most differentially expressed ones in a very comprehensive way," he says. Velculescu published that work in Science on Oct. 20, 1995