Department of Biological Sciences, Columbia University, New York (USA) • Martin Chalfie, University Professor and former chair of the Department of Biological Sciences at Columbia University, shared the 2008 Nobel Prize in Chemistry for his introduction of Green Fluorescent Protein (GFP) as a biological marker. He was born in Chicago, Illinois, but from the age of eight grew up in its northern suburb of Skokie, where he spent considerable time swimming and learning to play the classical guitar. He entered Harvard in 1965 with an interest in science, but by the time he graduated four years later, he had no confidence in his ability to do research and no clear plan for what to do next. After working for two years as a janitor, interviewer for an educational company, dress salesman, and high school teacher, he found himself working in a lab where, to his astonishment, an idea he had yielded publishable results. This success bolstered his confidence enough to apply to graduate school. He returned to Harvard where he obtained a Ph.D. in 1977 in Physiology with Robert Perlman. From 1977-1982 he did postdoctoral research with Sydney Brenner at the MRC Laboratory of Molecular Biology, Cambridge, England and then joined the Columbia faculty as an Assistant Professor in 1982. As a postdoctoral fellow, Martin Chalfie and John Sulston established the first genetic model for mechanosensation using the nematode Caenorhabditis elegans. He and his lab at Columbia subsequently conducted molecular, genetic, and electrophysiological studies to understand the molecular basis of mechanosensory signaling and neuronal differentiation using C. elegans. His studies include work on neuronal degeneration, microtubule structure and function, neuronal outgrowth, the genetic control and maintenance of neuronal cell fate, and mechanosensory transduction and its modulation. Dr. Chalfie is a member of the National Academy of Sciences and the National Academy of Medicine, a fellow of the American Academy of Arts and Sciences, and a foreign member of the Royal Society. He is a past president of the Society for Developmental Biology and current president of the American Society for Cell Biology. He also chairs the Committee on Human Rights of the National Academies of Sciences, Engineering, and Medicine. Biographies often say what people did, but rarely what sustains them and makes them happy. For him this would be his wife, Tulle Hazelrigg, and daughter, Sarah. Both make him laugh, share their love, and keep him on his toes.