Reductions in cardiac infarct size can be achieved in ischaemic preconditioning, a procedure which subjects the heart to intermittent, non-lethal cycles of ischaemia and reperfusion. Similar cardioprotection can be induced upon preconditioning distal tissues such as the upper limb, and this procedure is called remote ischaemic preconditioning. Nano-sized, cell-derived vesicles known as exosomes…