Dr. Xi is studying signaling events that drive squamous cell carcinomas (SCCs), a common form of skin cancer. She focuses on WNT signaling, which is an important player in cell fate determination. It appears that WNT signaling is essential for SCC tumor formation, but exactly where and how it is required remains unknown. She is dissecting the activity of WNT signaling during the progression from normal epithelial cells to benign papillomas, and then to malignant SCC tumors. She is also investigating the critical downstream effectors of WNT signaling in this process, in order to identify improved targets for cancer therapeutics.