TNF and narcolepsy: Furthermore, in patients with excessive daytime sleepiness disorders, such as sleep apnea and narcolepsy, peripheral levels of IL-6 and TNFα are elevated and appear to mediate sleepiness and fatigue [80]; indeed, in a pilot study, Etanercept, a TFNα antagonist, significantly and markedly reduced daytime sleepiness in patients with sleep apnea [81].