MAPT and Alzheimer disease: Moreover, it is investigated whether microglia from both sporadic (CRISPR‐Cas9‐based APOE4 lines) and familial (APPNL‐G‐F/MAPT double knock‐in mice) AD models show reduced levels of TREM2 and lack of phagocytic activity toward ePtdSer‐positive Aβ plaques.