In T1D, Todd et al. reported in an IL-2 clinical trial that a single dose ranging from 0.04 to 1.5 MIU/m2 body surface area induced transient downregulation of NK cells’ percentage in circulation at 90 minutes followed by an expansion of the population above baseline in an IL-2 dose-dependent manner (51). Here, IL2 is linked to type 1 diabetes mellitus.