In another example, Ha and co-workers combined the chemo-drug combretastatin A-4 (CA4) with a tumor-targeting biotin portion and a PS Zn (II) phthalocyanine (ZnPc), in which a ROS-sensitive aminoacrylate linker was introduced for the controlled release of CA4 during PDT [125]. The gene discussed is CA4; the disease is neoplasm.