CMTM4 and neoplasm: PSC-derived exosomes, containing miR-5703, were further demonstrated as promoting PDA tumor cells growth through a miR-5703 mediated downregulation of CMTM4 and the consequent activation of PI3K/Akt pathway [73], while miR-21 was shown to promote PDA tumor cell migration by enhancing Ras/ERK pathway activity [74].