These findings suggest that S100A4(+)/HIF-1α(−) GBM cells are co-opted along preexisting vessels in the vascular-rich area; they are adjacent to S100A4(+)/HIF-1α(+) tumor cells with activated HIF-1α/VEGF signaling in non-Ps perinecrotic lesions. Here, HIF1A is linked to glioblastoma.