However, it was shown that attenuation of ROS, particularly superoxide anions through Sestrin2/Nrf2 signaling, can downregulate TGF-β/Smad and platelet-derived growth factor receptor-beta (PDGFRβ) and enhance cigarette smoke-mediated emphysema in the mice model [197–199]. This evidence concerns the gene PDGFRB and pulmonary emphysema.