In their recent paper, Kleinberger et al. [27] used an in-house ELISA to measure levels of sTREM2 in patients with AD and FTD, as well as in patients with homozygous TREM2 mutations that cause or are predicted to cause loss of function of TREM2 (p.T66M and p.Q33X). Here, TREM2 is linked to frontotemporal dementia.