Owing to dramatically improved survival compared with traditional standard chemotherapy, dozens of anti-CTLA4, anti-PD-1 and anti-PD-L1 antibodies have been approved for several tumor therapies, including non-small cell lung cancer (NSCLC), colorectal cancer, melanoma, etc. However, they can also lead to drug-induced autoimmunity, termed immune-related adverse events (irAEs), which can target virtually any organ system within the body and range in severity from mild to life-threatening. The gene discussed is CTLA4; the disease is non-small cell lung carcinoma.