Another study showed significant upregulation of Grp78, p58 and Grp94 mRNA as well as increased expression of UPR genes (Atf3, Chop, and Trib3) in islets from prediabetic db/db mice (Chan et al., 2013), strongly indicating the involvement of chronic increased ER stress in the beta cells of T2D diabetic mice. This evidence concerns the gene HSPA5 and type 2 diabetes mellitus.