PDGFRB and leiomyosarcoma: Pazopanib, which targets vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR), has shown promising activity in patients with advanced STS.60 Compared with historical controls receiving second-line chemotherapy, pazopanib prolonged PFS and OS in patients with STS (including leiomyosarcomas and synovial sarcomas).