PARK7 and diabetes mellitus: Furthermore, DJ-1 gene (PARK7) was found to be down-regulated in pancreatic islets of patients with type 2 diabetes mellitus (T2DM) [49], and a low serum concentration of IGFBP-1 is associated with gestational diabetes mellitus (GDM), unfavorable metabolic profile, glucose intolerance and risk of diabetes mellitus [50, 51], which are similar to our results.