To confirm our results from the BS-PCR sequencing, showing that the methylation of the 5′-end region of the GSTP1 promoter is more specific to HCC than that of the 3′-end region in a large sample of tissues, we developed an MSP assay targeting the CpG sites that showed higher HCC specificity when analyzed by BS-PCR sequencing (Fig. 1B) in the 5′-end promoter region. Here, GSTP1 is linked to hepatocellular carcinoma.