(A) Confirmation of HPV-related gene promoter methylation for ALDH1A2, OSR2, GATA4, GRIA4, and IRX4 in the combined cohort 1/2 (Heidelberg) (n = 100) by MassARRAY. Each symbol represents the mean of all CpG units in a sample amplicon. Bars denote medians. ***P < 0.001, Mann-Whitney U test. (B) Correlation between gene promoter methylation (mean of all CpG units) and transcript levels of 30 samples from cohort 2. Statistical nonparametric comparison for correlation between methylation and expression values was performed by Spearman’s Rho method (r is indicated). *P < 0.05, **P < 0.01, 2-tailed Spearman’s Rho test. (C) Confirmation of the discriminating methylation signature of 5 gene promoters in validation cohort 3 (Leipzig) (n = 70). Each symbol represents the mean of all CpG units in a sample amplicon; bars denote medians. ***P < 0.001, Mann-Whitney U test.