Assertion: narcolepsy's brain | /r/CapableOf | regulate wakefulness or rem sleep
Facets:
Source sentences:
text: In rare cases, narcolepsy can be caused by traumatic brain injury, tumors, or other diseases affecting the parts of the brain that regulate wakefulness or REM sleep.  
text: While it is unclear what the exact cause of narcolepsy is, medical experts do know that people with narcolepsy have low levels of hypocretin (a chemical in the brain that regulates wakefulness and REM sleep) in their spinal fluid.
text: In rare cases, narcolepsy can be caused by traumatic brain injury, tumors, or other diseases affecting the parts of the brain that regulate wakefulness or REM sleep.