We demonstrated that only methylation of a subset of the CpG sites in the GSTP1 promoter, the 5′ end of the position −48 nucleotide [nt] relative to the transcription start site, was methylated specifically in HCC and also confirmed that the methylation of the CpG sites of the GSTP1 gene at the 3′-end promoter region occurs in the normal liver and appears to be liver specific compared to DNA isolated from 12 other normal tissues. The gene discussed is GSTP1; the disease is hepatocellular carcinoma.