Arthur and Marian Hanisch Memorial Professor of Chemistry, California Institute of Technology. Director since 1993. Assistant Professor of Chemistry and Biochemistry, Hunter College, City University of New York 1980-82. Columbia University: Assistant Professor 1983-85, Associate Professor 1985-86, Professor of Chemistry and Biological Sciences 1986-89. California Institute of Technology: Professor of Chemistry 1989 to date, Arthur and Marian Hanisch Memorial Professor of Chemistry 1997 to date. Named a MacArthur Foundation Fellow 1991, the American Academy of Arts and Sciences Fellow 1991, the American Philosophical Society Fellow 2000 and National Academy of Sciences member 2002. Named Outstanding Director 2006 by the Outstanding Director Exchange, Recipient of the Willard Gibbs Award 2006, Recipient of the American Chemical Society ("ACS") Breslow Award 2003, ACS William H. Nichols Medal Award 1997, Columbia University Medal of Excellence 1992, ACS Garvan Medal 1992, Mayor of New York's Award in Science and Technology 1988, ACS Award in Pure Chemistry 1988 and the Alan T. Waterman Award of the National Science Foundation 1985. Member of the Gilead Sciences Scientific Advisory Board. Director, GeneOhm Sciences Inc. 2001-05.