Several studies have shown that most p-tau variants (e.g., p-tau181, p-tau217, p-tau231 and p-tau235) share common features: all are highly specific for AD, levels in CSF increase during preclinical AD, and associate well with in vivo Aβ and to a lesser degree, tau pathology [1, 19, 20, 22, 45]. Here, MAPT is linked to Alzheimer disease.