CD274 and renal cell carcinoma: Avelumab (MSB0010718C) is a fully human IgG1 anti-PD-L1 monoclonal antibody [47] which showed promising results in phase Ib clinical studies in patients with metastatic Merkel cell carcinoma [48], advanced unresectable mesothelioma [49], ovarian cancer [50], NSCLC [51], gastric or gastroesophageal junction cancer [52], refractory metastatic urothelial carcinoma [53], and renal cell carcinoma [54].