Many of the homeobox genes, developmental genes with roles in cancer that were reported to be hypomethylated (42), were included in this group (representing ∼7% of the c5 genes, Supplementary Figure S5F). The Polycomb repressive mark was previously associated with longer DNA hypomethylated segments referred to ‘canyons’ and ‘valleys’ (62,63), consistent with patterns observed in our gene group c5. Here, LBX1 is linked to cancer.