This population is characterized by the expression of markers such as TREM2 or APOE, genes that were previously associated with genetic risk factors for AD and other neurodegenerative disorders, although the functional role of this cell subset is still unclear (Butovsky et al., 2014; Keren-Shaul et al., 2017; Deczkowska et al., 2018). This evidence concerns the gene APOE and Alzheimer disease.