Treatment of fibroblasts from COPD patients with hemin to activate HO-1 results in reduced cellular senescence, improved mitochondrial function, and reduced ROS production [122] Since Nrf2 activates many other antioxidant genes in addition to HO-1, this suggests that activators of Nrf2 and inhibitors of Keap1 might be even more effective against oxidative stress in COPD. Here, KEAP1 is linked to chronic obstructive pulmonary disease.