One asymptomatic male patient (UK FIPA 1), identified prospectively after genetic screening, had a GH-secreting pituitary microadenoma (IGF-1 = 1.5 × upper limit of normal) and a 1 cm gastrointestinal stromal tumor; after three years of medical therapy, his pituitary adenoma was successfully operated on, while he remains under surveillance for the gastrointestinal stromal tumor. The gene discussed is IGF1; the disease is gastrointestinal stromal tumor.