MAPT and Alzheimer disease: We also aimed to clarify how CSF sTREM2 levels differ between individuals with clinical FTD syndromes due to AD versus FTLD pathology (as determined by their CSF neurodegenerative biomarker profile), as well as to establish whether sTREM2 levels correlate with levels of other CSF biomarkers previously explored in AD: T-tau, tau phosphorylated at position threonine 181 (P-tau) and Aβ42.