Although somewhat unexpected, the consistency of our observations and the findings by others[39-41] suggest that we may have to re-evaluate the current thinking about the function of MMP-9 in COPD and suggests a need to study the ratio MMP-9/TIMP-1 in COPD as well as in the concomitant presence of osteoporosis. The gene discussed is MMP9; the disease is chronic obstructive pulmonary disease.