PSEN1 and chronic obstructive pulmonary disease: Furthermore, with microarray analysis, we found lots of DE genes were implicated in multiple biological pathways, such as response to oxidative stress and regulation of apoptosis pathways, and some DE genes, such as Ppargcla, Itgb1, Kcnma, Ptgs2, and Psen1, may play the role of antioxidative stress and antiapoptosis in the rat model of COPD.