Increased pyruvate metabolism by the enzyme lactate dehydrogenase (LDH), as measured by the resulting lactate formation, correlates with the expression of the pyruvate importer or monocarboxylate transporter 1 (MCT1), which is an independent marker of poor prognosis in ccRCC [14,15]. Here, SLC16A1 is linked to nonpapillary renal cell carcinoma.