In this series, the frequency of hypopituitarism (deficit of either ACTH, TSH, GH, or LH/FSH) was 31%, in tumors 1–19 mm, 61% in tumors 20–29 mm, and 82% in tumors >30 mm in largest diameter (P < 0.01); multi-hormonal deficiency was also associated with larger tumors (P < 0.005). The gene discussed is POMC; the disease is hypopituitarism.