 CO has been shown to be protective in experimental models of Acute Lung Injury ALI, including hyperoxia and endotoxin exposure, bleomycin, ischemiareperfusion, and ventilator-induced lung injury VILI. At low doses, CO has been shown to confer tissue protective effects in these ALI models. In addition, CO has been shown to decrease inflammation, enhance phagocytosis, and improve mortality in models of sepsis including endotoxemia, hemorrhagic shock, and cecal ligation and puncture CLP. CO has also been shown to have beneficial therapeutic effects in pre-clinical models of disease including pulmonary hypertension, vascular injury, and transplantation. Furthermore, multiple human studies have demonstrated that experimental administration of several different concentrations of CO is well tolerated and that low dose inhaled CO can be safely administered to subjects in a controlled research environment. 