Our group is working on cancer genetics, using the zebrafish genetic system to clarify developmental pathways subverted in human leukemias and solid tumors. The zebrafish animal model provides a powerful system for genetic analysis of vertebrate embryogenesis, organ development and disease. This model is unique within vertebrates in its capacity for “forward” genetic analysis, through use of phenotype-driven mutational screens and readily accessible transparent embryos. These properties make the zebrafish an ideal system for gene discovery based on gene function, an advantage that is very useful in dissecting pathways of gene action and identifying genes that are either activated (oncogenes) or inactivated (tumor suppressors) during malignant transformation.