In contrast to monocytes, the pDCs in the peripheral blood circulation of T1D group showed a significantly higher frequency of pDCs expressing IFN-α than HC subjects (40.48 ± 8.0% vs 9.38 ± 1.6% in unstimulated), indicating that the pDCs are in an activated state in the subjects with T1D (p = 0.02) (Fig. 5e). This evidence concerns the gene IFNA1 and type 1 diabetes mellitus.