Previously, he was director of the Human Genetics Informatics group at the Whitehead Institute Center for Genome Research from 1996 on and from 2001-2004 ran an independent research group as the Pfizer Fellow in Computational Biology at the Whitehead Institute for Biomedical Research. His lab focuses on computational approaches to understanding the genetics of disease with a strategy of integrating powerful techniques from human and mouse genetics. His recent research focus is aggressive application of these approaches in major common disease areas, particularly Crohn’s disease and autism.