TREM2 and frontotemporal dementia: Finally, in a study investigating 64 individuals with FTD, soluble TREM2 levels did not differ between FTD overall or in a particular clinical subtype of FTD; however levels were significantly higher in GRN mutation carriers as well as FTD individuals with AD-like CSF profiles (t-Tau/ Aβ 1–42 ratio > 1.0) [152].