Imatinib was associated with the severity of hypoglycemia in GIST patients.204 Studies showed enhancement of B-cell survival by imatinib, potentially contributing to the observed hypoglycemic effects.205 Sunitinib is associated with the incidence of hypoglycemia in 15–19% of patients who present mostly 4 weeks after treatment.206 Regression of pancreatic islets, modulation of IGF-1 (insulin-like growth factor 1) signaling, and decreased glucose uptake are the proposed hypotheses. Here, IGF1 is linked to gastrointestinal stromal tumor.