In the identified studies, GLP-1R PET/CT most frequently localised the insulinoma in cases of negative conventional imaging and should therefore be conducted as a next step—if locally available—in cases with negative MRI and CT but biochemically suspected insulinoma, as Somatostatin receptor imaging (SRI) and EUS show higher false negative results in the reported literature (Figure 5). The gene discussed is GLP1R; the disease is pancreatic insulinoma.