To validate the observed transcriptomic changes, suggestive of a switch in the GAMs phenotype upon 7aaRGD administration, we performed immunohistochemical co-staining for IBA1 (ionized calcium-binding adapter molecule-1, a marker of myeloid cells) and Arg1 (arginase-1, a hallmark marker of immunosuppressive/proinvasive GAMs) on brain sections from glioma-bearing mice. This evidence concerns the gene ARG1 and central nervous system cancer.