MMP2 and nonpapillary renal cell carcinoma: In the present study, the serum and urinary levels of MMP-2 and -9 and TIMP-1 and -2 were measured in patients with oncocytoma or clear cell renal cell carcinoma (ccRCC) in order to verify whether these molecules may offer a potential non-invasive biomarker to provide useful clinical information for kidney carcinoma.