According to the current Endocrine Society Clinical Practice Guidelines, hypoglycaemia causes can be divided into two categories based on clinical status: (1) patients who appear to be healthy (endogenous hyperinsulinemia, insulinoma, post‐bariatric hypoglycaemia, autoimmune insulin hypoglycaemia, malicious hypoglycaemia, hypoglycaemia due to antibodies to insulin and insulin receptors), and (2) patients who look to be unwell or medicated (malnutrition, IGF‐2‐secreting non‐islet cell tumour, drugs, alcohol, hypopituitarism and hypoadrenalism).2 The gene discussed is INS; the disease is pancreatic insulinoma.