Compared to controls, protein levels of MEF2C were increased in the diaphragm of the COPD patients (Figure 6A), whereas protein levels of myocyte-enhancer factor (MEF)2D, YY1, MyoD, Pax7, serum response factor (SRF) and BRG1/BRM-associated factor (BAF)60c did not differ between the study groups (Figures 6B–6C and 7A–7D). Here, MYOD1 is linked to chronic obstructive pulmonary disease.