As discussed above, the increased transcriptional activity of protective Idd3 alleles translates into higher levels of IL-2 production by auto-reactive CD8+ T cells in response to antigenic stimulation and, controls the size of the Treg cell pool in the pancreatic lymph nodes of NOD mice[10,22] These results show that IL-2 gene variation may affect the balance between islet-specific auto-reactive T cells and Foxp3+ Treg cells, and consequently precipitate T1 D. In Sgouroudis et al., we asked if Il2 allelic variation potentiates Foxp3+ Treg cell-mediated regulation of T1D[9]. The gene discussed is IL2; the disease is type 1 diabetes mellitus.