HLA-targeted gene approach studies have reported the strongest susceptible HLA allele associations for HLA class II genes, with HLA-DRB1*08:03 and HLA-DQB1*06:01 in Japanese PBC (10–12) and HLA-DRB1*08:01 in Italian PBC (13), US PBC (14) and UK PBC (15). This evidence concerns the gene HLA-DRB1 and primary biliary cholangitis.