Local infusion of a low-dose of the endotoxin lipopolysaccharide in rats, as a model of chronic inflammation, induces the loss of hypocretin neurons and increases the number of MHC class II-positive microglia in the lateral hypothalamus. Microglia-mediated inflammation might be a trigger for the loss of hypocretin neurons during narcolepsy (Maurovich-Horvat et al., 2014). The gene discussed is HCRT; the disease is narcolepsy.