The discovery of cancer-causing genes has provided us with the exciting opportunity to begin to understand the molecular pathology of ovarian cancer. Activation of several of these genes including HER-2/neu, myc, ras, and p53 has been described in some ovarian cancers (Table 2). In addition, some proto-oncogenes such as the EGF receptor (erbB) and the M-CSF receptor (fms) are expressed along with their respective ligands in some ovarian cancers. Finally, for every oncogene that has been studied in ovarian cancer, there are at least a half-dozen that remain unexplored. In the future, when we have a better understanding of the molecular pathology involved in the development of ovarian cancer, this may allow us to better diagnose and treat, and eventually prevent, ovarian cancer.