In recent years, multiple studies have already unraveled the positive association between irAEs and HLA class I as well as HLA class II alleles, including HLA-DRB1*11:01 and pruritus, HLA-B27 and autoimmune encephalitis, HLA-DR15, HLA-Cw12 and adrenal insufficiency, HLA-Cw12, HLA-DR15, HLA-DQ7, and HLA-DPw9 with hypophysitis, HLA-DR4-DR53 and HLA-DR15 with thyroiditis, and HLA-B*35 and DRB1*11 with pneumonitis (18–21, 23, 32). The gene discussed is HLA-DRB1; the disease is Pruritus.