ROS1 and extraosseous osteosarcoma: These included ALK, BRAF, FGFR1–4, NTRK1–3, RET, and ROS1 kinase fusions in a wide range of sarcoma histologies, including IMT (62.1%), MPNST (4.9%), UPS of bone (4.3%), extraskeletal osteosarcomas (4%), UPS (3.6%), sarcoma NOS (3.8%), and LMS (1.9%) (Fig. 3a).