To study the effect of the TREM2 gene in AD pathogenesis, several mouse models were generated including TREM2-BAC x 5XFAD [85], TREM2 Humanized (common variant) x 5XFAD [86], and TREM2 Humanized (R47H) x 5XFAD [86]. The gene discussed is TREM2; the disease is Alzheimer disease.