Officials at the US Food and Drug Administration (FDA; Rockville, MD) are seeking to expand their use of biomarkers for evaluating drugs. The FDA already largely relies on biomarkers for evaluating drugs for treating HIV, according to Donna Mildvan of Beth Israel Medical Center (New York). She was speaking at a mid-April meeting, "Biomarkers and Surrogate Endpoints: Advancing Clinical Research and Applications," held at the US National Institutes of Health (NIH; Bethesda, MD). No one doubts that biomarkers are revolutionizing clinical research," says Scott Zeger of Johns Hopkins University School of Hygiene and Public Health (Baltimore, MD), noting that biomarkers are used as a substitute measure for clinical end points during therapeutic trials. Stepped-up efforts are under way to expand that success into other clinical areas involving diseases such as cancer and CNS disorders, according to NIH director Harold Varmus, who has been meeting periodically since 1997 with industry representatives to encourage that expansion. "The need for newer biomarkers is a bottleneck in drug development," he says.