CD226 and type 1 diabetes mellitus: A similar study using peripheral lymphocytes isolated from three pairs of monozygotic twins discordant for T1D and six pairs of monozygotic twins concordant for T1D showed altered methylation at 88 CpG sites in, genes including HLA, INS, IL2RB, and CD226, most of which are critical for initiating immune reactions against autoantigens.94