In conclusion, our study 1) demonstrates a new function for STK33 in several in vitro and in vivo experiments, namely tumor angiogenesis downstream of HSP90 chaperone while it 2) characterizes the role of the kinase in the activation of the HIF-1α transcription factor and its target gene, VEGF, in hypoxic cancers. This evidence concerns the gene HIF1A and neoplasm.