A phase 2 trial of avelumab (a human anti‐PD‐L1 IgG1 monoclonal antibody [mAb]) in patients with metastatic (m) MCC that was refractory to chemotherapy, demonstrated a 31.8% durable objective response rate, according to Response Evaluation Criteria in Solid Tumors version 1.1,13, 14 culminating in avelumab being the first FDA‐approved immunotherapy for MCC in March 2017. The gene discussed is CD274; the disease is Merkel cell skin cancer.