One much-studied, potential early detection approach, the use of the serum biomarker cancer antigen 125 (CA-125) and transvaginal ultrasound (TVU), was extensively examined in the Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial, including 78,216 women, with a median follow-up up to 13 years. The gene discussed is MUC16; the disease is cancer.