Moreover, even if a conclusion cannot be drawn due to the limited number of cases, it has been found that the D842V mutant GIST, along with those carrying PDGFRA exon 12 and exon 14 mutations, display a more favorable prognosis, while those with exon 18 non-D842V mutations have a more aggressive behavior (22). The gene discussed is PDGFRA; the disease is gastrointestinal stromal tumor.