TSPAN4 and cyst: It may be possible to unify these observations with the finding of the TSPAN4/PC1 colocalization on extracellular vesicles by suggesting that mitocytosis is defective in ADPKD and that low levels or the absence of PC1 or CU062 could be responsible for the accumulation of senescent mitochondria observed in cyst-lining cells; see Section 4.4.1.