TREM2 and Alzheimer disease: The high expression of ITM2B, an AD-related familial dementia gene (Liu et al, 2021; Rhyu et al, 2023; Vidal et al, 1999, 2000), in both mouse and human microglia lead to the investigation of potential functional interactions between BRI2 and TREM2 in microglia, given the emerging importance of microglia and the microglia-specific gene TREM2 in AD pathogenesis (Guerreiro et al, 2013; Schmid et al, 2002).