Representative immunohistochemical staining of clear cell renal cell carcinoma tissues with antibodies for FBP1, HIF-1α, HIF-2α, EPO and CA9 (DAB staining; magnification, ×200). FBP1, fructose-1,6-bisphosphatase; HIF, hypoxia-induced factor; EPO, erythropoietin; CA9, carbonic anhydrase IX.