Similar to the role of EC-SOD in the rat bleomycin model of BPD and PH inhibition of tissue necrosis factor (TNF-α) signaling by both pharmaceutical intervention and exposure to 7% CO2 caused reduced PH symptoms and reduced lung injury, indicating a role of TNF-α signaling in disease development [68]. This evidence concerns the gene SOD1 and bronchopulmonary dysplasia.