MAPT and early-onset autosomal dominant Alzheimer disease: Certain pathological conditions result in abnormal phosphorylation of tubulin associated unit (Tau) protein that plays a role in maintaining the stability of microtubules in axons.22 Some studies have shown that abnormal p-Tau levels indicate the formation of neurofibrillary tangles in the brain parenchyma.23 Many clinical studies have confirmed that the concentration of p-Tau protein in cerebrospinal fluid of patients with Alzheimer’s disease is significantly higher than that of healthy people.22