Among them, we find avapritinib, an inhibitor of c-KIT and PDGFRA activation loop mutants that has been approved by the Food and Drug Administration (FDA) for GISTs that harbor PDGFRA exon 18 D842V mutations [167], whereas dasatinib, an oral inhibitor of c-KIT, produced a positive response in one patient with PDGFRA D842V-mutant GIST in a Phase II trial, and is currently used off label for this molecular subtype [172]. This evidence concerns the gene PDGFRA and gastrointestinal stromal tumor.