Previously used groupings of CSF intervals for HCRT-1 concentrations (low (≤110 pg/ml), intermediate (>110 ≤ 200 pg/ml), and normal (>200 pg/ml)) were not strictly applied in this sample as these are most relevant in the diagnosis of narcolepsy [30, 60, 61]. The gene discussed is HCRT; the disease is narcolepsy.