Elevation of both circulating MMP-9 and WBC count have been considered risk factors or biomarkers for cardiovascular disease [10],[11],[12],[13],[14],[15],[16],[51],[52],[53], COPD [17],[18],[19], arthritis [20],[21],[22] and metabolic syndrome [23],[24], all of which are associated with subclinical inflammation and are promoted by smoking. This evidence concerns the gene MMP9 and chronic obstructive pulmonary disease.