HMOX1 and lung cancer: Oxidative stress, as is well known, has a pivotal role in cancerogenesis, in particular, the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) pathway is involved in chemoresistance in lung cancer through a stimulus to proliferation; in fact, an overexpression of HO-1 is related to higher tumor aggressivity [60].