Tao et al. (2020) found remarkably similar results: Gal-3 expression was upregulated in the brains of AD patients and APP/PS1 mice, another mouse model of AD; Gal-3 promoted Aβ oligomerization and fibrilization; Gal-3 knockout in APP/PS1 mice reduced amyloid plaque formation and decreased cognitive deficits; and Gal-3 bound microglial TREM2 to induce microglial activation and further Gal-3 expression. Here, APP is linked to Alzheimer disease.