PDGFRB and head and neck squamous cell carcinoma: For instance, Sorafenib—a RAF kinase, vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR) inhibitor [39]—was evaluated in phase II clinical trial of patients with R/M HNSCC and resulted in a partial response or disease stabilization in 40.7–51% of patients [40,41].