The best CSF measures for identifying patients with MCI and suspected AD (MCI-AD) were CSF measurement of Aβ42/total tau (t-tau) and Aβ42/hyperphosphorylated tau (p-tau) ratios, with a sensitivity of 94-97% and a specificity of 83-85% [13-15]. The gene discussed is MAPT; the disease is Alzheimer disease.