On the other hand, the presence of single-nucleotide polymorphisms in the promoter of MMP-12, such as the (-82) A/G allele of SNP rs2276109 or Asn357Ser (A/G) of rs652438, has been associated with reduced risk of developing COPD and better prognosis [46]. This evidence concerns the gene MMP12 and chronic obstructive pulmonary disease.