In this study, we focus on chondroitin sulfate proteoglycan 4 (CSPG4) as a potential immunotherapeutic target in chondrosarcoma based on the discovery that it is highly expressed in chemically-induced rat chondrosarcoma, and originally identified as rat chondroitin sulfate proteoglycan nerve-glial 2 (NG2), later to be shown to share 100% homology with human CSPG4 (17–19). Here, CSPG4 is linked to chondrosarcoma.