Paediatric solid tumours, such as osteosarcoma, gastrointestinal stromal tumours (GIST), synovial sarcoma, and neuroblastoma, have an overexpression of the platelet-derived growth factor receptor (PDGFR), while Ewing sarcoma and neuroblastoma have an overexpression of c-Kit. This evidence concerns the gene KIT and neuroblastoma.