PRKN and chronic obstructive pulmonary disease: Studies have found that skeletal muscles from COPD patients exhibit aberrant expression of mitophagy-related factors, including elevation of Bcl-2/adenovirus E1B interacting protein 3-like (BNIP-3L) protein and Parkin mRNA, and decreased expression of FUNDC1 protein and the LC3B-II/LC3B-I protein ratio [43].