An endoscopic ultrasound identified an inconclusive lesion in the pancreatic tail; however, a subsequent gallium-68 DOTA-exendin-4 PET-CT (Ga-68 GLP-1 PET) demonstrated marked uptake in the entire pancreatic tail, consistent with diffuse nesidioblastosis rather than a discrete lesion compatible with insulinoma (Fig. 1). The gene discussed is GLP1R; the disease is pancreatic insulinoma.