Both the medial frontal cortex, supra-marginal gyrus, and parietal lobe are abundant in hypocretin projection (30, 31), which can explain the reduced fALFF value in these regions among narcolepsy due to hypocretin deficiency, consistent with two previous positron emission tomography studies (7, 8). The gene discussed is HCRT; the disease is hyperinsulinemic hypoglycemia, familial, 4.