RASSF1 and hepatocellular carcinoma: This meta-analysis included 44 studies that reported the relationship of the promoter methylation of RASSF1A with HCC or the associated clinicopathological characteristics in patients with HCC, studies that investigated the promoter methylation levels of RASSF1A in both tissues and blood, case-control studies that regarded HCC and non-HCC people as cases (as confirmed from liver tissues and peripheral blood), and studies that reported the exact frequency of RASSF1A methylation in both cases and controls.