The most prominent of these associations concern birdshot chorioretinopathy (BSCR), ankylosing spondylitis (AS), Behçet's disease (BD) and psoriasis, which involve HLA-A*29:02, HLA-B*27, HLA-B*51, and HLA-C*06:02, respectively (2–10). The gene discussed is HLA-B; the disease is ankylosing spondylitis.