Assertion: narcolepsy's cause | /r/RelatedTo | a loss of cells
Facets:
value: in the brain
type: LOCATION
Source sentences:
text: Narcolepsy with cataplexy has a known cause, related to a loss of cells in the brain that secrete hypocretin (also called orexin).
text: The cause of narcolepsy is related to the loss of cells in the brain that secrete hypocretin.