HCRT and narcolepsy: Mean levels of IGFBP3 in age and sex matched narcolepsy patients (all with low CSF hypocretin-1) versus controls were 59.4±3.4 ng/ml (n = 11) and 58.0±4.5 (n = 11) ng/ml in serum and 31.2±2.1 ng/ml (n = 27) and 29.0±1.9 ng/ml (n = 35) in CSF respectively.