Recently, a study performed by Keren-Shaul et al. (2017) specified a subtype of microglia named disease-associated microglia (DAM), which develops in two steps in Alzheimer’s disease (AD)-transgenic (Tg-AD) and triggering receptor expressed on myeloid cells 2 (TREM2)–/– Tg-AD mouse brains by transcriptional single-cell analysis (Da Mesquita and Kipnis, 2017; Ozaki et al., 2022). This evidence concerns the gene TREM2 and Alzheimer disease.