P4HB and type 2 diabetes mellitus: We observed a significant upregulation of GRP78 (also known as HSPA5) in type 2 diabetes compared with IGT and NGT pancreatic islets (p=0.004) (Fig. 3a) and a significant increase of x-box binding protein-1 (XBP1) and of PDIA1 (also known as P4HB) in type 2 diabetes (p=0.02) (Fig. 3b,c), suggesting the activation of ER stress pathways.