During hypoglycemia periods, the serum insulin level was significantly increased in diazoxide-unresponsive patients (mean insulin level, 29.6 ± 32.7 μIU/ml) compared with the diazoxide-responsive patients (mean insulin level, 11.5 ± 8.6 μIU/ml, P < 0.05). The gene discussed is INS; the disease is Hypoglycemia.