CD4 and type 2 diabetes mellitus: The flow cytometry strategy for the analysis of Tr1 lymphocytes is shown in Fig. 1A. When the levels of Tr1 lymphocytes (defined as CD4+CD49+LAG3+IL10+) were analyzed in both patients’ groups (severe and mild), we observed a significant fold increase in these cells in comparison with control individuals, either as percentage or absolute number of cells (Kruskal wallis test p = 0.0009; mean of controls = 1 ± 0.12, Mild T2DM = 2.3 ± 0.42 and Severe T2DM = 2.6 ± 0.37, p = 0.016 and p = 0.0003 respectively Fig. 1B, and data not shown).