ARF6 and cancer: Ca2+-mediated scramblase activation has been shown to induce externalisation of phosphatidylserine (PS) during MV formation, whilst in cancer cells, where shed MVs have been extensively studied, the small GTPase RhoA and associated proteins, as well as GTP binding protein ADP-ribosylation factor 6 (ARF6), have been shown to contribute cytoskeletal rearrangements and membrane budding during MV formation [57,58].