HLA-DRB1 and autoimmune hepatitis: In a first GWAS for AIH [27], involving 649 adult AIH patients and 13,436 controls, followed by replication in 451 patients and 4103 controls, the strongest genome-wide significant (P < 5 × 10−8) association signal for SNP rs2187668 was found at 6p21.32, and HLA imputation assigned the SNP signals to HLA-DRB1*03:01, which is considered the primary AIH susceptibility allele (Table 1); HLA-DRB1*04:01 was identified as another independent (i.e., secondary) AIH susceptibility allele by conditional forward stepwise logistic regression analysis [32].