INS and Alzheimer disease: More importantly, we also found that the protein level of insulin-degrading enzyme was decreased upon STZ treatment in the cortex of either WT (Fig. S2, A and E) mice or 3x Tg AD mice (Fig. S2, G and K), and the phosphorylation of mammalian target of rapamycin (mTOR) was increased in the cortex of 3x Tg AD mice (Fig. S2, G and J) due to the less protein level of mTOR, but not in WT mice (Fig. S2, A and D).