CTLA4 and neoplasm: Since 2011 when ipilimumab (anti-CTLA4) was first approved by the FDA for patients with metastatic melanoma, various ICBs, such as nivolumab, pembrolizumab, atezolizumab, avelumab and durvalumab, have continuously been approved by the FDA for treating a wide range of malignancies, with approval likely for additional tumor types in the near future.