This substitution occurs both on classical alleles HLA-DRB1*08:01 (which is strongly associated with PBC in Europeans) and on HLA-DRB1*08:03 (which is known to be associated with PBC in Japanese/Chinese populations [4, 5, 25] and thus offers a potential explanation for the HLA-DRB1*08 associations seen in these different populations. This evidence concerns the gene HLA-DRB1 and primary biliary cholangitis.