Previous studies showed protective functions of TREM2 overexpression by facilitating Aβ42 phagocytosis and inhibited proinflammatory responses in cultured primary microglia, reducing AD‐related neuropathology in mice APPswe/PS1dE9 and ameliorating tau pathology a tau mice model (Jiang et al, 2014, 2016b). Here, TREM2 is linked to Alzheimer disease.