CA9 and cancer: Therefore, expression of HIF-1-a, HIF-2-a, and their downstream targets such as VEGF, GLUT1, carbonic anhydrase 9 (CA9), phosphoglycerate kinase 1 (PGK1), and lysyl oxidase (LOX) was evaluated and their association with prognosis and chemotherapy-response seemed to vary between pediatric cancer entities [21].