They found that the inhalation of these drugs helped maintain the balance of superoxide dismutase (SOD) and ROS through the activation of the Nrf2/HO-1 signaling pathway significantly reduced the PF score of mice, and reduced the number of M2 macrophages and the secretion of TGF-β; which in turn improved the condition of the mice with PF [79]. The gene discussed is HMOX1; the disease is pemphigus foliaceus.