According to the 2011 guidelines from the National Institute on Aging and the Alzheimer's Association (Jack et al., 2011), reliable biomarkers for AD only included the levels of Aβ1-42, total tau, and phosphorylated tau in the cerebrospinal fluid (CSF), which are expensive, invasive, and infeasible for screening. The gene discussed is MAPT; the disease is Alzheimer disease.