TMEM8B and colonic neoplasm: To identify whether aberrant methylation of the NGX6 promoter in colon cancer cell lines reflects an epigenetic event occurring in primary colorectal cancer tissues, we further examined the NGX6 promoter mathylation status in the 40 pairs of colorectal cancers and adjacent normal colorectal mucosa using methylation-specific PCR (some are shown in Figure 3B).