CRC tissues with the repression of PEPT1 had higher levels of DNA methylation in the sequenced region (−264 bp to +36 bp) compared with adjacent non-tumor colonic tissue samples, especially in the 25th to 30th CpG sites, suggesting that hypermethylation occurs at the PEPT1 promoter in CRC (Fig. 3C). Here, SLC15A1 is linked to neoplasm.