HSP90AB1 and neoplasm: Loss of Rab27 abolished the release of EVs as well as Hsp70 and Hsp90 (Fig. 6b) without altering Hsp70/90 and AChE expression by tumor cells (Supplementary Fig. 8A), resulting in a blockade of the catabolic response in myotubes to tumor cell-conditioned media (Fig. 6c).