TREM2 and Alzheimer disease: Interestingly, some AD risk genes (APOE, BIN1, PICALM, CD2AP, SORL1, GRN, PLD, PLD3, INPP5D, MEF2C, EPHA1, PTK2B, CLU, and TREM2) are directly or indirectly associated with endosome–lysosome and autophagy pathways and regulate tau degradation (reviewed elsewhere [14,193,194]).