We are implementing an innovative, experimental medicine strategy to deliver immunotherapy that systematically targets the key aetiological pathways in T1D.7, 19, 20 DILfrequency and its forerunner, ‘Adaptive study of IL-2 dose on regulatory T cells in type 1 diabetes’ (DILT1D)20, 21 are specifically designed to analyse the effects of Proleukin on the human peripheral immune system in blood to establish the dose and frequency of administration required to preferentially enhance Tregs over Teffs. Here, IL2 is linked to type 1 diabetes mellitus.