CD68 and central nervous system cancer: The high level expression of these RTKs and their ligands, together with the results of nuclear staining of p–ERK and p-AKT in CD68- or CD105-positive cells, suggest concomitant activation of RAS-RAF-MEK-MAPK cascade and PI3K-AKT pathway in both TAMs and immature vessel endothelial cells in RMPAhigh gliomas.