Hypomethylation is required for FOXP3 binding. (A) Illustration of subsets of activated T cells (left panel) and expression of FOXP3 (right panel). (B) Enrichment of FOXP3 binding in hypomethylated Treg gene loci upregulated by FOXP3 and at the FOXP3-repressed IL7RA locus. AFM intron 1 was used as a control. Data are represented as mean + standard deviation of 3 donors; paired t test (2-tailed).