Studies have also shown that Mstn is upregulated and involved in COPD-related skeletal muscle dysfunction (Plant et al., 2010; Polkey et al., 2019; Sancho-Muñoz et al., 2021); however, the molecular mechanisms regulating the expression of Mstn, and particularly its interaction with irisin, in the pathogenesis of skeletal muscle dysfunction in COPD have not yet been elucidated. This evidence concerns the gene FNDC5 and chronic obstructive pulmonary disease.