CSPG4 and neoplasm: CSPG4 positive tumor cells, incubated together with PBMC and r28M, underwent a caspase 3 and 7 related pathway, strong signals of the caspase 3 subunits (17 and 19 kDa) and caspase 7 subunit (20 kDa) were detected (Fig 6, lane 3).