In this study, we observed that a relatively high proportion of Tregs from children with T1D show low expression of key Treg effector genes such as IL2RA, FOXP3, CTLA4, TGFB1 and high expression of CD226, IL4R and GZMK, which are connected with Treg dysfunction60,61,71,72 or T cell senescence107. This evidence concerns the gene CTLA4 and type 1 diabetes mellitus.