Among patients treated with anti‐PD‐1, melanoma showed the highest incidence of irAEs (62.3%, 33 of 53), followed by renal cell carcinoma (54.8%, 17 of 31), head and neck cancer (51.8%, 44 of 85), esophageal cancer (39.4%, 13 of 33), lung cancer (38.9%, 44 of 113), urothelial carcinoma (30.9%, 34 of 110), other cancers (30.0%, 3 of 10), and gastric cancer (29.3%, 12 of 41). Here, PDCD1 is linked to head and neck cancer.