Several GWASs have identified a genetic loci of susceptibility, including FAM13A, CHRNA5/3, IREB2, MMP3/MMP12, TGFB2, and HHIP. The HHIP gene has been related to the FEV1/FVC ratio, FEV1, or both parameters of lung function, which are essential for diagnosis and COPD classification according to GOLD guidelines. This evidence concerns the gene TGFB2 and chronic obstructive pulmonary disease.