CA9 and neoplasm: All PDGCAs expressed markers of tumor epithelial and stem cells (EPCAM, CDH1, KRT18, CA9, CD24, CD133), stromal and extracellular matrix components (COL3A1, COL5A1, DCN, PDGFRA, and PDGFRB), and mesenchymal stem cells (CD73, CD105, CD90) (Figure 6a,b).