HLA-B57 and HLA-B*27 are associated with drug hypersensitivity (69, 70) and autoimmune diseases such as ankylosing spondylitis (71, 72), respectively, while HLA-B*52:01, which is a protective allele in HIV-1-infected Japanese individuals, is also associated with Takayasu arteritis (65, 66, 68, 73, –, 75) and ulcerative colitis (65, 68, 76). The gene discussed is HLA-B; the disease is ankylosing spondylitis.