Genes such as AGER, GPR126, GSTCD, HTR4, THSD4, and TSN1 are associated with lower lung function in the general population while other ones, including CHRNA3/4/5/7, CHRNB3/4, HHIP, and FAM13A, are associated with COPD development and the severity of airway obstruction [12]. This evidence concerns the gene HHIP and chronic obstructive pulmonary disease.