On the other hand, several studies have suggested that FTLD patients (including bvFTD) display higher levels of CSF NfL and/or lower ratio of phospho-tau/tau compared to healthy controls or patients with other neurodegenerative or psychiatric diseases, including e.g., AD (Skillbäck et al., 2014; Meeter et al., 2016; Vijverberg et al., 2017; Abu-Rumeileh et al., 2018; Goossens et al., 2018; Meeter L.H.H. et al., 2018; Niikado et al., 2018). Here, MAPT is linked to Alzheimer disease.