TREM2 and Alzheimer disease: Although the function of TREM2 in AD pathology is partly unclear, it is hypothesized a role of TREM2 in clearing the soluble Aβ aggregates and other toxic debris and controlling the inflammatory reactions elicited by the AD pathology (Hsieh et al., 2009; N'Diaye et al., 2009; Kleinberger et al., 2014).