Within our T1D cohort, classical monocytes CD14+CD16-, CD196+ monocytes and CD194+ monocytes were significantly higher in T1D-group-A than in T1D-group-B, indicating that heterogeneity in circulating monocytes with specific migratory capacities and possibly function can develop during the progression of diabetes. Here, CCR4 is linked to type 1 diabetes mellitus.