In this study, we show that combinedanti-PD-1/GITR mAb elicited a potent antitumor immune response resulting in significanttumor growth suppression in a highly clinically relevant ovarian cancer model; moreimportantly, anti-PD-1/GITR mAb show a clearly synergistic antitumor effect withcisplatin and paclitaxel, two most commonly used chemotherapeutic drugs for EOCpatients, in murine ID8 ovarian cancer (C57BL/6 origin) and 4 T1 breast cancer (BALB/corigin) models with two strains of mice with different genetic backgrounds. The gene discussed is TNFRSF18; the disease is breast cancer.