MRC1 and neurodegenerative disease: Ccl4hi TBI microglia share markers with disease-associated microglia (DAM); Cenpfhi TBI microglia are proliferating microglia; Apoehi TBI macrophages share markers with DAM and lipid-associated macrophages; Ccl8hi TBI macrophages share defining markers with Mrc1+ Lyve1+ resident CNS-associated macrophages, thus connecting the biology of TBI with findings in other neurodegenerative diseases (Jordão et al., 2019; Li et al., 2019; Jaitin et al., 2019; Hammond et al., 2019; Keren-Shaul et al., 2017), and acute injuries (Wahane et al., 2021).