Tian Xu is professor and vice chairman of Genetics at Yale University and a Howard Hughes Medical Institute investigator. His lab is working to understand the mechanisms of tumorigenesis and metastasis using Drosophila and mouse models. Notably, Dr. Xu has developed the powerful piggyBac transposon mutagenesis system, which has allowed investigators to perform forward genetics in mammalian models. This approach should prove instrumental in the identification of important genes involved in human diseases.