TREM2 and Alzheimer disease: Using time response assays, they further demonstrated that DAMs are first activated independently of Trem2. However, in the late stages of AD, Trem2 is needed to activate protective programs of lipid metabolism and phagocytosis (Keren-Shaul et al., 2017), although others suggested that Trem2 is required for microglia transition to DAMs (Nugent et al., 2020).