Treating healthy MSCs with melatonin increased the PrPC in exosomes isolated from MSCs through the upregulation of miR-4516 and, when CKD-MSCs are treated with these exosomes from melatonin-treated healthy MSCs, a significant increase in the levels of angiogenesis-associated proteins through miR-4516-PrPC signaling [68]. Here, PRNP is linked to chronic kidney disease.