NFE2L2 and chronic obstructive pulmonary disease: A deficiency in Nrf2 activity may aggravate oxidative damage and inflammatory injury, which is closely related with oxidative stress and inflammatory-related diseases, including cancer, Alzheimer’s disease, Parkinson's disease, chronic obstructive pulmonary disease, asthma, atherosclerosis, diabetes, multiple sclerosis, osteoarthritis, and rheumatoid arthritis [29-32].