In their list of proven and validated biomarkers of AD, they included the detection of Aβ-amyloid and tau-protein deposits on positron emission tomography (PET), the cerebrospinal fluid (CSF) concentration of Aβ42, the ratio of Aβ42 to Aβ40, and the levels of total tau (t-tau) and p-tau 181 in the CSF [8]. This evidence concerns the gene MAPT and Alzheimer disease.