CD44 and osteosarcoma: Several of these innovative tools based on HA-functionalized liposomes have become an excellent CD44-mediated intracellular delivery system for doxorubicin (DOX) or photodynamic anticancer therapy in osteosarcomas: Chol-SS-mPEG/HA-L (211), HA-LsDOX (212), ALN–HA–SS–L–L/DOX (213), and HA-es-ZnPP (214).