The trend of methylation status increased progressively from normal (lowest methylation), CIN1, CIN2, CIN3, CIS, to SCC/AC (highest methylation) in the genes SOX1, PAX1, ZNF582, HS3ST2 and POU4F3 with statistical significance (test for trend was calculated by Kendall’s Tau correlation = τ, P<0.05) (Fig 2). This evidence concerns the gene SOX1 and in situ carcinoma.