Nevertheless, GWAS studies conducted on larger samples have not confirmed these results, finding other gene variants associated with COPD, including genomic regions close to Ras and Rab interactor 3 (RIN3), cytochrome P450 family 2 subfamily A member 6 (CYP2A6), and desmoplakin (DSP) [6,8]. This evidence concerns the gene CYP2A6 and chronic obstructive pulmonary disease.