DUSP1 and obstructive sleep apnea syndrome: In contrast, Hoffmann et al. found that, in human coronary artery endothelial cells, IH increased manganese SOD activity via an increased dual-specificity phosphatase 1 (DUSP1) expression, and that overnight IH induced the expression of DUSP1 in mononuclear cells and granulocytes from patients with OSA [55].