The research interests of our laboratory include the mechanisms of DNA damage response, chromatin remodeling, epigenetic modifications, and their roles in tumorigenesis. As a principle investigator, I have extensive expertise and motivation necessary to successfully carry out the research projects that are supported by various funding agencies. The research conducted in my laboratory results a number of manuscripts published in leading journals. Eight trainees from my laboratory have successfully become independent investigators, established their own laboratories, and generated scientific contributions in the cancer research field. Our current research mainly focuses on the role of protein poly(ADP-ribosyl)ation in DNA damage repair and cancer chemotherapy. Poly(ADP-ribosyl)ation is an unique posttranslational modification induced by DNA damage. Targeting poly(ADP-ribosyl)ation by PARP inhibitors suppresses DNA damage repair and selectively kill tumor cells with DNA damage repair defectives. Our recent studies not only reveal the basic molecular pathway of poly(ADP-ribosyl)ation in DNA damage repair, but also suggest novel therapeutic targets in this pathway for future cancer treatment. In addition, we recently developed small molecule inhibitors specifically targeting dePARylation enzymes for cancer chemotherapy.