Among patients with PDGFRA D842V variants, the overall response rate was 91%, with the median duration of response being 27.6 months (95% CI, 17.6 to not reached).17 The study subsequently led to the approval of avapritinib for patients with PDGFRA D842V variant–positive GIST as the first-of-class therapy for GIST harboring a PDGFRA exon 18 variant. The gene discussed is PDGFRA; the disease is gastrointestinal stromal tumor.