The importance of neuroinflammation and microglia in Alzheimer’s disease has been highlighted by multiple GWAS, which have identified a number of single polymorphisms associated with risk for development of Alzheimer’s disease in several immune related genes, including TREM2, CD33, BIN1, and CR1 (Efthymiou and Goate, 2017). The gene discussed is TREM2; the disease is early-onset autosomal dominant Alzheimer disease.