CHRNA3 and chronic obstructive pulmonary disease: With regard to the correlation between genetic polymorphism and risk of developing COPD, the literature states that some genetic polymorphisms of the CHRNA3/5 and EPHX1 gene may be associated with loss of pulmonary function and development of COPD in Caucasian and Asian population, and several studies have associated CHRNA3/5 with an increased risk of pulmonary neoplasia [9,10].