PDCD1 and ovarian carcinoma: Interestingly, patients with hypercalcemic small cell carcinoma, a rare and highly aggressive type of ovarian cancer, have a more active immune microenvironment, express high levels of PD-L1, and respond better to immunotherapy. In a recent clinical trial, after undergoing optimal tumor resection, four patients underwent additional chemotherapy as well as anti-PD1 therapy.