Subgroup analyses stratified by sample type showed that RASSF1A gene promoter hypermethylation was significantly associated with HCC risk (blood: OR = 6.93, 95% CI = 4.12–11.65, P < 0.001; tissue: OR = 7.12, 95% CI = 4.78–10.59, P<0.001). This evidence concerns the gene RASSF1 and hepatocellular carcinoma.