PDGFRA and gastrointestinal stromal tumor: The approval of imatinib mesylate (Gleevec®, Novartis Pharma, Basel, Switzerland), an oral inhibitor of KIT and platelet-derived growth factor receptor, alpha polypeptide (PDGFRA), to treat metastatic GIST by the USA FDA in 2002 has markedly changed the outcomes and treatment options for GISTs[12].