TNF and obstructive sleep apnea syndrome: Besides CRP, tumor necrosis factor-alpha (TNF-a) is a well-established modulator of systematic inflammation and has been proposed as a key biomarker for the onset and progression of OSA; chronic intermittent hypoxia, a key characteristic of respiratory pathology in OSA, can induce TNF-a expression and lead to cardiovascular complications, while TNF-a inhibition has been shown to ameliorate OSA progression [5].