CSPG4 is a proteoglycan that plays a role in cell proliferation and migration, stimulates endothelial cell motility during microvascular morphogenesis and may also inhibit neurite outgrowth and growth cone collapse during axon regeneration. CSPG4 is expressed on more than 90% of human melanoma tissues and cultured cells. It is a target of specific diagnosis and immunotherapy with antiidiotypic antibodies due, in part, to its roles in growth control, adhesion, cell-substratum interactions, and cell-cell contacts (PMID: 10587647; 11278606).