CTLA4 and neoplasm: Blockade of CTLA‐4 can induce anti‐tumor immunity.12 Ipilimumab is a fully human monoclonal antibody (mAb) that improves overall survival in patients with metastatic melanoma and elicits a long‐term survival benefit in a subset of patients.13 Ipilimumab became the first immune checkpoint‐targeted therapy to receive approval for clinical use in the USA and Europe in 2011.