TREM2 and Alzheimer disease: In AD, several molecules associated with microglial inflammation have been implicated, including triggering receptor expressed on myeloid cells 2 (TREM2), cluster of differentiation 33 (CD33), ATP-binding cassette sub-family A member 7 (ABCA7), Src homology 2 domain-containing inositol phosphatase 1 (SHIP1), and apolipoprotein E (APOE) [11].