PTPN22 and type 1 diabetes mellitus: The genetic architecture of mouse and human T1D is remarkably similar, with variants affecting multiple immune genes and pathways in common between both species, including IL-2, IL-2 receptor, CTLA-4, IL-10, the HLA region, PTPN22, and IL-7R (69, 70) For example, single nucleotide polymorphisms (SNPs) in the human homologous Il2 region were also associated with T1D susceptibility, identifying the IL-2 pathway as potentially shared in the pathogenesis of disease in both species (71).