IL2 and type 1 diabetes mellitus: An IL-2 dose determination study was performed in a small cohort of T1D patients in 2013.20 This randomized placebo-controlled phase I/II trial was under taken to define the lowest IL-2 dose that could induce Treg cells in 24 adult T1D patients randomized in groups of 6patients to either placebo or IL-2 at doses of 0.33, 1 or 3 million international units per day for a 5-day course.