Patients with 18q del exhibited significantly decreased percentage of CD4+CD25+ FOXP3+Treg and CD4+CD25+FOXP3+Helios+Treg (Helios+ cells originate from the thymus) cell subpopulations in comparison not only with healthy controls but also with T1DM groups (p < 0.00011 and p < 0.00027, respectively) (Figure 2A, B). Here, CD4 is linked to type 1 diabetes mellitus.