CSPG4 and melanoma: Next, to gain an insight into the potential mechanism by which anti-CSPG4-(PDD) exerted cytotoxicity towards melanoma cells, CSPG4-high A375 and CSPG4-low WM-1361 cells were quantified after four and seven days of treatment with PBS and anti-CSPG4-(PDD) (Figure 5C).