Tmem119 has been reported to be IHC-positive in microglia but not in peripheral immune cells (Bennett et al., 2016) and was used to distinguish resident microglia from migrated peripheral cells in Alzheimer’s disease (Satoh et al., 2016) and glioma (Haage et al., 2019). This evidence concerns the gene TMEM119 and early-onset autosomal dominant Alzheimer disease.