TREM2 and Alzheimer disease: Therapeutic approaches targeting TREM2—including antibodies or gene therapy [111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165,166,167,168,169,170,171,172,173]—should be promising approaches in AD, but they may require careful optimization based on disease stage, mutation type, and microglial state.