Indeed microglia were found to be critical to glioma development98 and macrophages are abundant in neurofibromas and MPNSTs.99,100 These macrophages are recruited by macrophage colony-stimulating factor (M-CSF).100 Pharmaceutical inhibition of macrophages has been shown to slow down pNF progression.100 Therefore, in addition to tumorous glial cells, these microenvironmental macrophages are also potential therapeutic targets for neurofibroma and glioma. Here, CSF1 is linked to central nervous system cancer.