DKK4 and renal cell carcinoma: A RCC-specific signature including 10 up- or downregulated proteins (such as MMP-9, podocalyxin (PODXL), Dickkopf-related protein 4 (DKK4), carbonic anhydrase IX (CAIX) and ceruloplasmin) were found in the urinary EVs from RCC patients by proteomics [67].