Trem2-knock out mice have altered microglial phagocytosis and larger infarct volumes after cerebral ischemia (Takahashi et al., 2005; Kawabori et al., 2015), supporting earlier studies where XPro1595 was found to promote neuroprotection by improving phagocytosis of dying neurons and cell debris in demyelinated lesions in an animal model of multiple sclerosis (Karamita et al., 2017). Here, TREM2 is linked to multiple sclerosis.