PDGFRA and gastrointestinal stromal tumor: The efficacy of olaratumab, an anti-PDGFRA monoclonal antibody, has been examined in 31 patients with metastatic and/or unresectable GIST (but only 20 out of 31 patients were evaluable) in 2017 [245]; no CR and PR were observed and only 5 patients had SD [245].