3.3. Receiver Operating Characteristic (ROC) Curve for Using PD-1, PD-L1, CTLA-4, CTLA-4/PD-L1, and PD-1/PD-L1 to Distinguish between Ovarian Cancer and Benign Ovarian Cystic Lesions. The gene discussed is CTLA4; the disease is ovarian carcinoma.