Among the glycolytic enzymes, pyruvate kinase M2 (PKM2) and lactate dehydrogenase A (LDHA) excretion were significantly correlated with htTKV, whereas PKM2 excretion was negatively correlated with eGFR, suggesting that PKM2 is an important biomarker of kidney volume in patients with ADPKD before renal-function decline. The gene discussed is PKM; the disease is autosomal dominant polycystic kidney disease.