As well as phagocytosis-related receptors, TREM2 is another important receptor on microglia that maintains cell function in AD and has been extensively studied lately from both the gene and protein level (Krasemann et al., 2017; Shi et al., 2017; Filipello et al., 2018; Sayed et al., 2018; Long et al., 2019; Yin et al., 2019; Zhou et al., 2019). This evidence concerns the gene TREM2 and Alzheimer disease.