As has previously been reported, the direction of effect of DNA methylation is dependent on the location of methylation.37, 38 Previous studies have shown that methylation within the transcriptional start site of the promoter is well known to repress gene expression while methylation within the gene body results in more variable expression.37, 38 Therefore, both GSTM3 expression and HSPA6 expression may contribute to the onset of HCC in African Americans. This evidence concerns the gene GSTM3 and hepatocellular carcinoma.