AIF1 and central nervous system cancer: The untreated canine glioma microenvironment for oligodendroglioma and astrocytoma was highly enriched for Iba1+ macrophages, and microglial cells but not CD3+ T or CD20+ B cells, both of which were found in very small numbers within the TME consistent with previous findings in canine glioma patients analyzed at necropsy[36–39].