CSPG4 and melanoma: Chondroitin Sulfate Proteoglycan 4 (CSPG4), also known as neuron-glial antigen 2 (NG2) and high molecular weight-melanoma associated antigen (HMW-MAA), was initially identified on melanoma cells, but has since been shown to be expressed by a wide variety of cancer types, as well as on CICs in many of the cancer types analyzed (Campoli et al., 2010).