CA1 and cancer: Members of the CA family contain 16 isoenzymes that differ from one another in terms of tissue distribution, cell localization, catalytic activity, and resistance to inhibitors. They perform several functions, such as transport of carbon dioxide, pH regulation, ion transport, formation of stomach acidity, bone resorption, calcification, and tumorigenesis during cancer cell development and invasion [9,10]. CA I and II are both cytosolic enzymes present in significant numbers in erythrocytes.