Examples include FOXP3 promoter/Treg-specific demethylated region (TSDR) hypermethylation and reduced FOXP3 expression in CD4+ T cells from Latent Autoimmune Diabetes in Adults (LADA) and fulminant T1D patients, and enrichment of TSDR-methylated FOXP3+IFN-γ+ cells in T1D cohorts (26–28). This evidence concerns the gene CD4 and type 1 diabetes mellitus.