The protein expression of cathepsin D in T2D mice significantly increased by 55 % at 8 weeks and 118 % at 20 weeks in the cortex, and by 46 % at 8 weeks and 64 % at 20 weeks in the hippocampus, compared to nondiabetic control (Fig. 2a, b). The gene discussed is CTSD; the disease is type 2 diabetes mellitus.