When we examined CGIs of candidate genes, we observed unexpectedly that the mean methylation levels of the CGIs of four of the five genes were not statistically different between CIN II/III and CIN I/normal groups (Figure 3A), indicating that during CIN development, the overall methylation status of the examined CGIs of NKX6-1, SOX1, LMX1A, and ONECUT1 did not change. This evidence concerns the gene NKX6-1 and cervical squamous intraepithelial neoplasia.