In addition, peptide R reduced the presence of CD31/VEGF positive cells and Arg-1-expressing vessel-like structures in the tumor core, suggesting that a reduced aberrant intratumoral vascularization could represent a further important anti-tumoral mechanism of peptide R. Anti-angiogenic therapies in GBM patients indicate the promising benefits of these approaches [52]. This evidence concerns the gene PECAM1 and glioblastoma.