A study by Bloom and colleagues also implicated the gene responsible for hypoxia, EGLN2 (Egl-9 family hypoxia inducible factor 2), playing a role in COPD; furthermore, CYP2A6 acts independently of the nicotine metabolism and hence can be responsible for COPD in both smokers and non-smokers [37]. Here, CYP2A6 is linked to chronic obstructive pulmonary disease.