Figure 4. Examples of methylation status of the genes at chromosome 9q33-34. (A) MS-PCR (methylation-specific PCR) shows the hypermethylation status of ABO, TSC1, DAPK1, and DBCCR1, all of which are located at chromosome 9q33-34 in 2 tumor samples (T1 and T2). M, methylated allele; U, unmethylated allele. For both the DAPK1 and DBCCR1, hypermethylation occurs at the same time as hypermethylation of the ABO gene promoter. There is no hypermethylation of the TSC1 gene promoter, which is close to the ABO gene. (B) Methylation-specific melting curve analysis (MS-MCA) of a tumor and normal adjacent tissue. The curve pattern of the tumor demonstrates that, in the tumor, both methylated and unmethylated alleles are found; in normal epithelium, only an unmethylated allele is present.