Indomethacin (IMC), a COX-2-targeting ligand, is linked to Cy7-TCF to form a small-molecule-based PTA (Cy7-TCF-IMC), which can be self-assembled into nanosheets in aqueous solution for passive targeting to the tumor site via the EPR effect, providing a chance for COX-2 targeting system. This evidence concerns the gene PTGS2 and neoplasm.