We next used a semiquantitative RT‐PCR method to profile the expression of MMP‐2/MMP‐9/MMP‐12, NGAL and IL‐6 transcripts in PBMCs isolated from blood samples of 19 COPD‐S patients and 12 healthy‐S participants (for the patients’ characteristics, see the Table S3). This evidence concerns the gene MMP2 and chronic obstructive pulmonary disease.