The suppression rate of 18-day UCB-Tregs to PBMCs at a 1:1 ratio was negatively correlated with the course of diabetes (r = -0.770, p = 0.015) but not with age, daily insulin dose (INS dose), insulin dose-adjusted A1c (IDAA1c), FCP, 2-h PCP, 2-h C-peptide AUC, GADA, IA-2 A, and ZnT8A. Here, INS is linked to diabetes mellitus.