TREM2 and Alzheimer disease: AD model mice crossed with Trem2- or Dap12-deficient strains revealed that the TREM2/DAP12 complex is involved in microglial activation around amyloid plaques to prevent accumulation and diffusion of β-amyloid (Aβ) (Wang et al., 2015, 2016; Yuan et al., 2016; Keren-Shaul et al., 2017).