In light of CSF p-tau being significantly increased in AD compared to controls, several studies have shown a clear correlation between CSF p-tau and Aβ pathology measures (Bateman et al., 2012; Barthélemy et al., 2020; Suárez-Calvet et al., 2020), with changes in CSF p-tau also being observed several years prior to symptom onset, and when only subtle changes in Aβ pathology measures are detected. This evidence concerns the gene MAPT and Alzheimer disease.