PECAM1 and glioblastoma: For IDH-WT glioblastoma, the results revealed an increased P-gp and mitochondria expression by tumor cells in the peritumoral and intratumoral area compared with the normal one and a significantly higher expression in the peritumoral area compared with intratumoral one as well as a progressively increased CD31 and CD31 + mitochondria expression by ECs from the normal to the intratumoral area; although mitochondria + CD31 expression by ECs results is not significant in all three areas, an increased expression was appreciable in the intratumoral area.