Dr. Appella was among the first researchers to identify the tumor suppressor protein p53, and he has studied its roles in the cell and regulation by post-translational modification. He and his colleagues further identified a critical phosphatase that is upregulated by p53 following DNA damage. This phosphatase, Wip1 (PPM1D), is amplified or overexpressed in several human tumors. Dr. Appella’s research currently is focused on exploring the roles of Wip1 in cells and its contribution to tumorigenesis. They additionally are exploring how Wip1 is regulated. Finally, Dr. Appella’s laboratory is working to develop specific inhibitors of Wip1 that could be advanced to the clinic.