CDK4 and synovial sarcoma: The first group, in turn, could be broken down into three further subgroups: (a) sarcomas carrying translocations, such as SS18-SSX in synovial sarcomas (SS); (b) sarcomas with specific mutated genes, such as c-KIT or platelet-derived growth factor receptor (PDGFR) in GIST; and (c) sarcomas with high-level amplifications of chromosome 12 regions encompassing the MDM2 and CDK4 loci in well-differentiated liposarcomas (WDLPS) and dedifferentiated liposarcomas (DDLPS).