HSP90AA1 and prostate cancer: In addition, it is noteworthy that together with HSP70 and a set of EMT-associated biomolecules, HSP90 was found inside exosomes secreted by hypoxia-stressed prostate cancer cells [20]; such a presence of the chaperones among other exosomal components may be important for exosome formation and exosome-induced EMT/stemness, but this suggestion needs further examination.