HLA-DRB1 and primary biliary cholangitis: However, the protective DRB1*15:01-DQB1*06:02 haplotype may not be common to autoimmune liver diseases since the DRB1*11 and *13 alleles are resistant to PBC development in Caucasians and Japanese;[23], [31], [32] we cannot exclude the possibility that these associations are simply linkage markers for a yet undefined gene in AIH.