Pf-2545920, a well characterized highly potent and specific PDE10A inhibitor, and MCI-030, a novel PDE10A inhibitor that we recently reported to selectively inhibit colon cancer cell growth in vitro and adenoma formation in the Apc+/min−FCCC mouse model of colon cancer [25], were found to selectively suppress ovarian cancer cell growth. The gene discussed is PDE10A; the disease is malignant colon neoplasm.