While a clinical trial combining IL-2 with rapamycin showed transient deterioration in beta cell function, potentially due to the relatively higher IL-2 dose or the influence of rapamycin, which led to significant increases in natural killer cells and eosinophils, early studies on lower IL-2 doses in T1D have shown no acute degradation in beta cell function [260, 261]. This evidence concerns the gene IL2 and type 1 diabetes mellitus.