The high rate of therapeutic failure and tumor relapse currently seen in ovarian cancer could result from ineffective targeting of ovarian cancer stem cells. Ovarian cancer stem cells are a population of self-generating cells that are believed to be resistant to chemotherapy. Dr. Cheng is using a mouse model his laboratory developed, called the K-ras+/Pten(-) ovarian cancer model, that mirrors the disease process, precursor lesions and clinical behavior of the human disease with great accuracy. Using this model, he is hoping to isolate ovarian cancer stem cells to understand their role in resistance to drugs and tumor relapse. He also plans to test whether Mullerian Inhibiting Substance and platinum will destroy ovarian cancer stem cells in these mouse models.