The 9.2.27 monoclonal antibody specifically binds to CSPG4 (chondroitin sulfate proteoglycan 4). CSPG4 is also known as MCSP (melanoma chondroitin sulfate proteoglycan) and NG2 (neural/glial antigen 2). The hybridoma secreting the 9.2.27 antibody was generated using a human melanoma cell extract as the immunogen. Tumor cells display a variety of antigens which have been defined by antibodies. Antibodies that specifically react with tumor-associated antigens are useful in understanding the biology of particular tumor types. Proteoglycans including chondroitin sulfate, keratan sulfate, dermatan sulfate and heparan sulfate are major components of the extracellular matrices of many animal cell types. Clone 9.2.27 has been shown to react with human melanoma cells, glioma cells, and proliferating brain endothelial cells. It did not react with fetal melanocytes, neuroblastoma LA-N-1 cells or a variety of carcinoma, lymphoid, and fibroblastoid cell lines. Additionally, neither white nor gray matter from the medulla oblongata, cerebellum or spinal cord of a normal human adult reacted with 9.2.27. Clone 9.2.27 has also been used in functional studies to investigate the role of chondroitin sulfate proteoglycans in human tumor cell systems. It has been shown to block melanoma cell spreading, exhibit antiproliferative effects on glioma cells in vitro and suppress glioma tumor growth in athymic nude mice models.