Affiliation: | 1. Departments of Chemical and Systems Biology and Developmental Biology, Stanford University School of Medicine, 269 Campus Drive, CCSR 3155, Stanford, CA 94305 (USA) http://chen.stanford.edu;2. Department of Chemistry, University of Pittsburgh, Chevron Science Center, 219 Parkman Avenue, Pittsburgh, PA 15260 (USA) http://www.pitt.edu/~deiters |