We found that zinc supplementation to highly invasive and angiogenic glioblastoma cells or to prostate cancer cells, either constitutively hypoxic or after induction of hypoxia, downregulates HIF-1a protein levels and inhibits HIF-1 activity, resulting in the inhibition of VEGF expression, angiogenesis and tumor cell invasiveness [9]. This evidence concerns the gene HIF1A and glioblastoma.