To date, several studies have showed that altered DNA methylation at several genes are associated with the initiation and progression of HCC, including p15 and p16[64], APC[65], SPINT2[66], SFRP1[67], TFP12[68], GSTP1[69] and RASSF1A[70]. The gene discussed is SFRP1; the disease is hepatocellular carcinoma.