Single nucleotide polymorphisms (SNPs) in the endothelial nitric oxide synthase (NOS3) [103], glutathione s-transferase p1 (GSTP1) [104, 105], tumour necrosis factor alpha (TNFA) [106], interleukin 10 (IL10) [107], microsomal epoxy hydrolase (mEH) [105], cholinergic nicotine receptor alpha3 (CHRNA3), and iron regulatory binding protein 2 (IREB2) [108] genes have all been shown to influence COPD development in AATD patients [108]. This evidence concerns the gene NOS3 and alpha 1-antitrypsin deficiency.