A GI irAE may appear at any time from the first to the tenth dose of CTLA‐4 inhibitor, even several months after it was last administered.13 The median onset time of GI irAEs has been reported to be one month after initiation of CTLA‐4 inhibitor, and 2–4 months after PD‐1 inhibitor.14 GI irAEs occur more frequently, severely and early in patients with a combination treatment of CTLA‐4 inhibitors and PD‐1 inhibitors.2 The risk factors of GI irAEs include use of NSAIDs and medical history of inflammatory bowel disease.13, 15. The gene discussed is CTLA4; the disease is inflammatory bowel disease.