Carbonic anhydrase IX (CAIX, 10) is an enzyme overexpressed in mesothelioma and breast cancer cells.105, 106, 107, 108 CAIX inhibitors specifically bind to the low-density lipoprotein (LDL) receptor on the surface of cancer cells to form receptor-LDL complexes, and is delivered into cancer cells through endocytosis (Figure 3I).105. Here, CA9 is linked to breast carcinoma.