PROM1 and cancer: In this respect, pioneering studies on mammalian prominin-1 have highlighted (i) new donor membranes as sources of EVs, like microvilli and primary cilia as well as retracting cell extremities at the entry of the mitotic rounding process, or the midbody at the end of cytokinesis, and (ii) the action of prominosomes on recipient cells, notably those in the cancer microenvironment.