RASSF1 and carcinoma: Among these 13 genes, the meta-analysis of p16, RASSF1A and APC genes methylation was performed between HBV-positive carcinoma tissues and HBV-negative carcinoma tissues, HBV-positive adjacent tissues and HBV-negative adjacent tissues and finally between HBV-positive carcinoma serums and HBV-negative carcinoma serums.