PDGFRA and gastrointestinal stromal tumor: Many research studies have evaluated the antitumor effects of antibodies against KIT [242–244] and CD40 [199] in mouse GIST models, and antibodies against PDGFRA [245], VEGF [246] and XmAb18087, an bispecific antibody targeting SSTR2 and CD3 simultaneously [217], in GIST patients.