PDGFA and synovial sarcoma: However, the anti-PDGFRA antibody olaratumab did not improve outcomes in a trial for advanced soft tissue sarcomas [66], suggesting that alternative strategies targeting this pathway may be needed, a dedicated SS trial needs to be designed, or that expression of PDGFA and its receptor may be more a marker of the cell-of-origin phenotype of SS [17] than of an important functioning driver of its neoplastic growth.