Ding et al. elegantly showed that cystic cell-derived EVs and urinary EVs from ADPKD patients promote cyst growth in Pkd1 mutant kidneys and tridimensional cultures via the activation of PKD-associated signaling pathways in recipient cells, as well as fibroblast activation and macrophage recruitment in the neighboring tissue. The gene discussed is PKD1; the disease is autosomal dominant polycystic kidney disease.