ERN1 and type 2 diabetes mellitus: The protein level of IRE1 was increased in the T2DM group (2.4-fold, p = 0.001), after metformin administration—by 1.99-fold (p = 0.021) and after PA treatment—by 1.45-fold (p = 0.045) vs. control (Figures 7(e) and 7(f)).