However, despite the key role for MFN2 and possibly MFN1 in mitophagy regulation in AEC2 cells, Mfn1iΔAEC2 and Mfn2iΔAEC2 mice did not develop lung fibrosis, suggesting that mitofusin-related mitophagy regulation might not be the most critical mechanism accounting for lung fibrosis in the Mfn1/2iΔAEC2 mice. The gene discussed is MFN1; the disease is pulmonary fibrosis.