However, staining with an antibody against LC3 (an autophagosome marker) colocalized with MitoSOX Red (used as a marker of mitochondria) in fibroblasts from COPD patients at senescent stage indicated autophagosome accumulation (Supporting Information Figure S5c), confirming a defect of mitophagy in COPD fibroblasts. The gene discussed is MAP1LC3A; the disease is chronic obstructive pulmonary disease.