CDK4 and gastrointestinal stromal tumor: Apart from GIST, a driver genetic aberration that can serve as a therapeutic target has been identified in only a minority of sarcomas, including ALK fusion in IMT targeted with crizotinib and other TKIs [45], PDGFb fusion in dermatofibrosarcoma protuberans (DFSPs) targeted with imatinib [46], and CDK4 amplification in WDLPS and DDLPS targeted with CDK4/6 inhibitors [47].