Inverse correlation of methylation and gene expression. (A) Log average gene expression is plotted on the y-axis and corresponding average β-values on the x-axis for 7 samples. Data for 6541 CpG sites corresponding to 3395 genes had significant signals on both expression and methylation arrays in more than 6 of the samples. Spearman correlation Rho = −0.17, P = 2 × 10⁻⁸⁸. (B) Examples of correlation between expression (y-axis) and β-values (x-axis) for 12 genes. (C) Average gene expression of Polycomb-associated genes according to average methylation levels in 10 samples, showing an inverse relation in this subgroup.