tDMRs within the MHC region. Pair-wise comparisons (six in total) of the MHC array-derived DNA methylation profiles were performed using t-statistics. A threshold of p-value < 0.001 was used. In total 90 tDMRs were identified. Vertical axis shows the log2 ratio of the two corresponding methylation profiles. Each line represents a tDMR (average size 2 kb). Black lines represent tDMRs that are more methylated in sample 1 of the comparison and grey boxes represent tDMRs that are more methylated in sample 2 of the comparison (the identities of the pair-wise comparisons are given on the right). The majority of tDMRs are present in comparisons with sperm. The locations of HEP amplicons, a track of the C+G content and the approximate positions of the MHC class I, II and II subregions and some landmark genes are also indicated. Class III region encoding for the C4 genes seems to be less methylated in liver.