TREML2 and Alzheimer disease: As a missense variant, TREML2 rs3747742‐C leads to a change of amino acids at 144 residue (p.S144G) of TREML2, and functional studies are warranted to determine whether the protective effects of TREML2 rs3747742‐C against AD susceptibility are related to the alteration of TREML2 protein and microglia functions.