FLT1 and Ewing sarcoma: Regorafenib treatment, as a multikinase inhibitor, including c-Kit, VEGFR1-3, BRAF, FGFR1, significantly increased the EFS in 100% (9/9) of sarcoma models, including osteosarcoma, rhabdomyosarcoma, and ES (Harrison et al., 2019), and is currently under evaluation in phase 2 clinical trial for patients with sarcoma subtypes, including ES (ClinicalTrials.gov identifier: NCT02048371).