PDGFB and gastrointestinal stromal tumor: Enhanced understanding of the molecular aberrations driving the inception and progression of several STS subtypes belonging to the first group (e.g., c-Kit mutations in gastrointestinal stromal tumors [GIST] or the 17;22 translocation leading to PDGF-B over-expression in dermatofibrosarcoma protuberans; [DFSP]), has resulted in clinical applications of effective targeted therapies (e.g. Imatinib mesylate) with significantly improved outcome [6].