CD63 and metabolic syndrome: Complemented by two other publications from the teams of Keisuke Ito and Xabier Ostreikoetxea, which respectively describe the role of (i) mitochondrial metabolism on CD63 function and (ii) the link between the reduced CD63<sup>+</sup> small EVs and dyslipidemia, these arguments highlight the key role of CD63 in the regulation of cholesterol homeostasis through exosomes and more widely small EVs in physiological and pathological conditions.