Moreover, an epigenome-wide association study in 52 monozygotic twin pairs discordant for T1D in three immune effector cell types (that is, CD4+ T cells, CD19+ B cells, and CD14+CD16− monocytes) showed significant enrichment of differentially variable CpG positions in T1D twins when compared with their healthy co-twins and healthy controls [144]. This evidence concerns the gene CD4 and type 1 diabetes mellitus.