In the central nervous system, studies on postmortem brain tissues of patients with Alzheimer’s disease (AD) have revealed increased phosphorylation of IRS1 at hSer312/mSer307, hSer616/mSer612, hSer636/mSer632, and hSer639/mSer635 compared with that in non-AD control subjects [13,14,15,16]. The gene discussed is IRS1; the disease is early-onset autosomal dominant Alzheimer disease.