Tumors have elaborate mechanisms that prevent recognition and destruction by a host immune system. For instance, ovarian cancer can escape the immune system by fostering a highly suppressive environment in the peritoneal cavity, the fluid-filled gap between the wall of the abdomen and the organs within the abdomen. Some scientists believe tilting the balance from an immune-suppressive to an immune-active environment may be required for effective ovarian cancer therapy. In his study, Dr. Zhang is focusing on a protein called CD73 on the surface of ovarian cancer cells, which seems to prevent immune cells, called T cells, from attacking tumor cells. While CD73 is present on most tissues, too many copies of it are on ovarian cancer cells. In a mouse model of ovarian cancer, Dr. Zhang has used certain chemicals to reduce levels of CD73 and was able to improve T cells’ ability to fight the tumor. When he lowered CD73 and increased T cell activity, he was able to cure tumor-bearing mice. In his research, he aims to elucidate how CD73 suppresses the immune response and what kind of treatments may be developed to counteract it.