Cytotoxic T-lymphocyte antigen 4 (CTLA-4) inhibitors increase the risk of hypophysitis, and programmed cell death protein 1 (PD-1) and its ligand (PD-L1) inhibitors are associated with autoimmune thyroid disease and type 1 diabetes.4,5,6,7 Interestingly, human leukocyte antigen (HLA) class II genes confer significant risk for the development of corresponding autoimmune disorders outside the use of ICI therapy.8 However, little is known regarding the HLA antigen basis for development of specific irAEs and survival after these unwanted effects. This evidence concerns the gene PDCD1 and autoimmune thyroid disease.