Many explorations have shown that immune checkpoint testing is a reliable way to assess the patient’s response to immunotherapy, which is blossoming into the backbone of cancer treatment, while AML patients with high expression of conventional immune checkpoints [such as programmed cell death 1 (PDCD1, best known as PD1)] did not well benefit from immunotherapy based on most clinical trials, and these are closely related to immune complications in AML patients. The gene discussed is PDCD1; the disease is cancer.