It is well known that the CSF levels of tau are elevated in AD patients (Zetterberg and Blennow, 2013; Babić et al., 2014; Blennow et al., 2015; Babić Leko et al., 2018), and this was also confirmed in tau transgenic mice model (Barten et al., 2011). Here, MAPT is linked to Alzheimer disease.