CD4 and ovarian carcinoma: For example, intraperitoneal injection of induced pluripotent stem cell (iPSC)-derived NK cells have been shown to enhance the recruitment of both CD4+ and CD8+ T cells to the peritoneum in tumor-naïve mice, and iPSC-derived NK cells also enhanced the efficacy of PD-1 blockade in tumor-bearing mice in ovarian cancer model.44