Reduced or lost protein expression of the tumor-suppressing gene Rb2/p130 may play a key role in ovarian cancer, says a study in the May 1 issue of Clinical Cancer Research.Researchers at the Sbarro Institute for Cancer Research and Molecular Medicine in the Center for Biotechnology at Temple University in Philadelphia analyzed 45 primary ovarian cancer samples. They found 40 percent of those samples had a decrease or total loss of Rb2 protein expression.