Patients belonging to T1D-group-A, as compared to T1D-group-B, revealed a more proinflammatory phenotype characterized by a lower percentage of FOXP3+ Treg, higher proportions of CCR4 expressing CD4 and CD8 T cell subsets, a lower Treg/Tconv ratio and an increased proinflammatory cytokine (TNFα/IFNγ) producing potential upon stimulation, while the anti-inflammatory IL-10 producing capacity was reduced. This evidence concerns the gene CCR4 and type 1 diabetes mellitus.