Although we did not determine the percentage of oxidative type I fibres immunohistochemically in our study population, the lower expression of the MYH7 gene (a surrogate marker for type I fibres as it encodes the type I myosin heavy chain isoform38) in COPD is indicative of a decreased oxidative fibre type percentage which is in line with literature. The gene discussed is MYH7; the disease is chronic obstructive pulmonary disease.