In an investigation of emphysema and airway inflammation, pretreatment with exogenous H2S (NaHS) attenuated ferroptosis, reducing PM2.5-induced emphysema and airway inflammation by upregulating the expression of nuclear factor erythroid 2- related factor 2 (Nrf2) and PPAR-γ, and inhibiting NCOA4-mediated ferritinophagy, thus restoring redox balance and inhibiting ferroptosis [62]. The gene discussed is NCOA4; the disease is pulmonary emphysema.