Specific lesions of LH orexin neurons, such as orexin peptide knockout or orexin cell ablation, can substantially alter normal timing of vigilance state transitions in response to external context (narcolepsy) (Lin et al., 1999; Ma et al., 2018), demonstrating the critical role of orexin for moment-to-moment sensorimotor control (Chemelli et al., 1999; Hara et al., 2001; Karnani et al., 2020). The gene discussed is HCRT; the disease is narcolepsy.