In a study of human peripheral blood immune cell profiles from long‐standing T1D patients, as compared to healthy controls, it showed a more active immune profile as demonstrated by a higher percentage and absolute number of neutrophils, monocytes, total B cells, and activated CD4+CD25+ T cells, while the abundance of regulatory T cells (Tregs) was reduced [63]. Here, CD4 is linked to type 1 diabetes mellitus.