Adenovirus-mediated transfer of a gene that enhances surfactant production improves lung function and confers resistance to Pseudomonas aeruginosa infection ( Figure 2 ) [49] . Adenovirus-delivered superoxide dismutase and catalase genes protected against hyperoxic-induced, but not ischemia-reperfusion-induced, lung injury [50] . More recent studies have demonstrated the therapeutic potential of overexpression of a number of genes, including angio poietin-1 [51] , HSP-70 [52] , apolipo protein A-1 [53] , defensin β2 [54] and the Na + ,K + -ATPase pump [55] .