In GBM, hypoxia and its downstream cellular responses, such as increased stem-like phenotypes and angiogenesis, are associated with tumor progression.38 The idea that areas of PPN represent a hypoxic niche for CD133+ GSCs has been supported by previous literature.11 However, the key molecular events that regulate GSCs' response to hypoxia remain unclear. This evidence concerns the gene PROM1 and neoplasm.