Furthermore, evidence from non-COPD contexts indicates that resistance training can modulate MMP-2 and MMP-9 expression in skeletal muscle, visceral adipose tissue and circulation, supporting a plausible link between improved protease–antiprotease balance and regular physical activity, though studies directly evaluating these pathways in COPD remain lacking [164]. The gene discussed is MMP9; the disease is chronic obstructive pulmonary disease.