Colin Stewart received his PhD from the University of Oxford where he studied interactions between teratocarcinomas, the forerunners of ES cells, and early mouse embryos. Following postdoctoral work with Rudolf Jaenisch he became a staff scientist at EMBL in Heidelberg. There he was instrumental in discovering the role of the cytokine LIF in maintaining mouse ES cells and subsequently in regulating embryo implantation. There he initiated his interest in the nuclear lamins and nuclear architecture. He continued his studies on the lamins, stem cells and epigenetics following relocation to the Roche Institute of Molecular Biology in New Jersey. In 1996 he moved to the NCI in Frederick, Maryland as Chief of the Laboratory of Cancer and Developmental Biology. Since June 2007 he has been a principal investigator at the IMB.