As shown by co-staining for the endothelial cell marker CD31 and the MC marker mMCP-6, MCs within experimental gliomas frequently showed a perivascular localization (with an average of 50% for both Ntv-a- and Gtv-a Arf−/− mice) (Figure 2A), but were also present within the tumor mass in both Ntv-a- and Gtv-a lines. This evidence concerns the gene PECAM1 and central nervous system cancer.