Likewise, polymorphisms in oxidative stress related candidate genes like gluthathione s-transferases (GSTs), microsomal epoxide hydroxylase (EPHX), or heme-oxygenase 1 (HMOX-1), have been associated with lung function decline and chronic obstructive pulmonary disease (COPD), a disease characterized by accelerated, progressive lung function loss [13], [14], [15], [16]. The gene discussed is HPGDS; the disease is chronic obstructive pulmonary disease.