I am interested in the balance between proliferation and differentiation during development and cancer, using a range of models including embryos of the frog Xenopus laevis, mammalian cells including ES cells, and mice. I am particularly interested in post-translational cell cycle-dependent regulation or proneural transcription factors; manipulating this regulation can have far reaching conseqences for both differentiation therapies in cancer, particularly of neurological origin, and for regerenative medicine. Our work in the nervous system is complimented by parallel studies on basic helix-loop-helix transcription factors in pancreatic and intestinal development and cancer.   I would assert that cancer is primarily a disease of differentiation. Ultimately, our studies on these fundamental mechanisms that co-ordinate proliferation and differentiation during development, and their application in stem cell and developmental models, will illuminate the pathways that are disrupted in tumorigenesis and point the way to new therapeutic interventions.