Colorectal cancer is a common malignancy that demands improved diagnosis and treatment. Our long-term goal is to facilitate the development of new treatments and preventive measures for colon adenoma and carcinoma formation. To achieve this goal, we rely on analyses of human tumor specimens to define the signaling pathways that are disrupted during colon tumor formation. We do this in juxtaposition with the genetic manipulation of signaling pathways in zebrafish as a model for studying intestinal cell development and differentiation.