Whereas it has been previously suggested that the mitochondrial biogenesis response in COPD muscle under basal conditions is suppressed based upon low PGC-1α and TFAM [14], other studies suggest no impairment in mitochondrial biogenesis based upon a normal PGC-1α transcript response to acute exercise [13, 60]. This evidence concerns the gene PPARGC1A and chronic obstructive pulmonary disease.