Although the serum level of IL-10 in patients with PD–T2DM is consistently lower than that in patients with PD, the possibility exists that a higher production of IL-10 in more severe forms of PD with T2DM co-morbidity serves as a compensatory mechanism that attempts to resolve the detrimental inflammatory condition associated with the disease over time. This evidence concerns the gene IL10 and type 2 diabetes mellitus.