CA9 and neoplasm: This is a consequence of oncogene activation, loss of tumor suppressor activity, and the ability of cancer cells to shift glucose metabolism from oxidative phosphorylation to glycolysis [15].These cells respond to the microenvironmental change brought on by enhanced glycolytic metabolism by upregulating key regulatory systems such as carbonic anhydrase 9 (CA-IX) which helps maintain the physiological intracellular pH that is necessary for cell function [16].