In addition, small subsets of genes encoding for regulatory factors and enzymatic processes that have been implicated in the pathogenesis of type 2 diabetes mellitus (T2DM) were profiled, including interferon regulatory factors (IRF), indoleamine 2,3-dioxygenase (IDO1) and kynureninase (KYNU). This evidence concerns the gene IDO1 and type 2 diabetes mellitus.