The presence of at least two or all the exosomes markers from three different categories including Alix (Anti-Apoptosis), Actin (cytoskeleton) and HSP70 (Heat-Shock Protein) alongside the absence of GRP94 (ER marker) in our Western blot data confirmed the purity of the exosomes isolated from both PCa cell lines studied (Figure 1B). Here, HSP90B1 is linked to posterior cortical atrophy.