TREM2 has been shown to be a risk factor for AD (Guerreiro et al., 2013), and activation of microglia in the brain of mouse AD models and human AD patients can occur through TREM2-dependent and TREM2-independent mechanisms (Keren-Shaul et al., 2017), and NF-κB activation can also be induced by TREM2 signaling (Zhong et al., 2017). Here, TREM2 is linked to Alzheimer disease.