CD33 and Alzheimer disease: DAM features unique transcriptional and functional characteristics [317], and are associated with altered expression of several genetic AD risk factors: apolipoprotein E (APOE), TREM2, progranulin and TYROBP (DAP12) are upregulated in DAM, whereas CD33, BIN1, PICALM and PLCG2 are downregulated [317–321].