TREM2 and Alzheimer disease: The results of this study demonstrated that added Gal-3 activated triggering receptor expressed on myeloid cells 2 (TREM2)–DAP12-dependent signaling in a dose-dependent manner (Boza-Serrano et al., 2019), indicating the role of Gal-3 as an endogenous TREM2 ligand, a key receptor driving microglial activation in AD, which is involved in the complex regulation of processes of phagocytosis, inflammation, and cell proliferation (Yuan et al., 2016; Gratuze et al., 2018; Figure 1B).