Caspase-3, Bcl-2 family, vascular endothelial growth factor and so on have been defined to be involved in lung epithelial cell apoptosis, thus causing lung damage and emphysema (Aoshiba et al., 2003; Demedts et al., 2006; Mouded et al., 2009; Zeng et al., 2012). Here, BCL2 is linked to pulmonary emphysema.