Imatinib mesylate, a targeted therapy as tyrosine kinase inhibitor of c-KIT and PDGFR-a, has become the standard therapy not only for recurrent or metastatic GIST, but also for the adjuvant treatment in adult patients following complete resection of KIT-positive GIST [9, 10]. The gene discussed is PDGFRB; the disease is gastrointestinal stromal tumor.