TNF and obstructive sleep apnea syndrome: Intermittent hypoxia and stress in patients with OSA can activate nucleic factor-kB, initiating an inflammatory cascade that leads to the release of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6).[5,14,15] Since these cytokines are implicated in the pathogenesis of PsA, therefore, early detection and targeted-intervention of OSA in patients with PsA seems important for improving diseases prognosis.[16–19] However, not all studies show clear causal relationship between OSA and PsA.