Single cells were isolated from tumor tissues of patients with high-grade serous carcinoma (HGSC) and expanded for 14 days in the presence of IL-2 under four different conditions: (1) control (W), (2) PD-1 antagonist (WI), (3) PD-1 antagonist + IL-15 + IL-21 (WIO), and (4) PD-1 antagonist + IL-15 + IL-21 + GITR-agonist (WIOG). The gene discussed is IL21; the disease is neoplasm.