High salt intake promotes tau protein phosphorylation in the mouse brain [94], and a high-salt diet leads to a decrease in NO levels, which directly leads to an increase in the activity of calcium-activating enzymes (calpains), which cleave p35 to p25, resulting in the abnormal activation of CDK5 and excessive phosphorylation of tau protein [95,96], which in turn leads to cognitive impairment. The gene discussed is MAPT; the disease is Cognitive impairment.