IRS1 and diabetic encephalopathy: Upregulating Pin1 expression in the hippocampus of mice with diabetic encephalopathy by stereotaxic injection of an AAV vector significantly increased the phosphorylation of IRS1, Akt, and GSK‐3β, which are downstream of the IR/IGF1R signaling pathway, while significantly decreasing Tau phosphorylation (Figure 6).