Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal malignancies of the digestive tract.1 The incidence is estimated at 10 to 15 cases per million people per year, representing 1% to 3% of all gastrointestinal cancers.2 Approximately 75% to 80% of patients have activating mutations in the KIT proto-oncogene (CD117). The gene discussed is KIT; the disease is gastrointestinal stromal tumor.