Therefore, in the present study we profiled, by gene expression analysis, 10 samples of untreated primary gastric PDGFRA mutant GIST, half carrying a D842V mutation and half carrying mutations other than D842V, supposing that the different clinical behavior of these two PDGFRA mutant subgroups could be supported by a different biological background. This evidence concerns the gene PDGFRA and gastrointestinal stromal tumor.