One such strictly Treg cell-specific epigenetic element was found at the CTLA4 locus, which harbors a risk allele for multiple autoimmune disorders, including rheumatoid arthritis, type 1 diabetes (T1D), Graves' disease, and systemic lupus erythematosus (Scalapino and Daikh, 2008). This evidence concerns the gene CTLA4 and type 1 diabetes mellitus.