Homozygosity for the risk alleles exhibited significantly higher ORs for HBV-related liver cancer/HCC risk than heterozygosity, suggesting that risk-associated HLA alleles have synergistic effects (Table 4; the OR of homozygotes of the DRB1*15:02 allele for HBV-related HCC = 9.82, P = 1.2 × 10–8). This evidence concerns the gene HLA-DRB1 and hepatocellular carcinoma.