PLXDC1 and glioblastoma: Taken together with the reported differences in TEM7 (PLXDC1) expression in the tumor-associated vessels of human and mouse tumors in situ76 and the recent report of divergent features in mouse and human brains including differences in astrocyte specialization and gene expression77, our observation of differences in the expression of both the integrin α3 subunit and CD151 on TECs in human and mouse GBM strongly suggests critical differences in the regulation of tumor-associated new vessel formation in the human and mouse.