CA9 and breast carcinoma: Therefore, we attempt to further expand the application of the IFLD strategy to degrade carbonic anhydrase IX (CAIX), which is a transmembrane protein that is overexpressed in progressive and invasive tumors, such as colon cancer, lung cancer, and breast cancer The expression of CAIX is hypoxia-dependent and regulated by hypoxia-inducible factor (23, 24).