CD4 and type 1 diabetes mellitus: However, these studies were conducted in healthy people, were not specific to type 1 diabetes and were characterisations of broad populations, e.g. CD4 and CD8 T cells, and not of population subsets and cytokines that are components of type 1 diabetes autoimmunity (e.g. central memory, effector memory and regulatory T cell [Treg cell] subpopulations).