AP homodimers and heterodimers have been found to be present in cancer cells through protein electrophoresis, inhibition by different inhibitors, and immunoassay with two monoclonal antibodies.4, 23 However, these methods cannot directly prove the formation of AP heterodimers rather than the coexistence of two AP homodimers or monomers on cells. The gene discussed is DHCR7-DT; the disease is cancer.