CSPG4 and neoplasm: Interestingly, while Hs 578T and D-10-0021 MG cells expressed similar levels of CSPG4 (Fig 1), Hs 578T failed to show improvement in cytotoxicity with all of the combinations tested (Tables 1 and 2), demonstrating that the surface CSPG4 density is not a critical determinant of tumor cell sensitivity to combination therapy.