PDGFRA and gastrointestinal stromal tumor: While some KIT and PDGFRA germline mutations have been identified among families with multiple GIST cases [24], [25] and a few studies have identified single nucleotide polymorphisms (SNPs) associated with soft tissue sarcoma incidence (MDM2[26]), survival (AhR[27]), or specific translocations common in some types of soft tissue sarcoma (XPG/ERCC5[28]), no studies have looked for inherited genetic risk factors for sporadic GISTs.