CD4 and type 1 diabetes mellitus: Consistent with the well-known deranged immune T-cell function, T1DM subjects exhibited lower circulating Treg (CD4+CD25+CD127−) cell percentages and reduced mRNA levels of transcription factors related to CD4+ Th differentiation, RORC and FOXP3, which are determinants for Th17 and Treg differentiation, respectively.