Assessment of inflammatory/immune cells recovered by lavage and lower respiratory tract ELF of HIV1− healthy nonsmokers, HIV1+ nonsmokers, HIV1− healthy smokers, HIV1− smokers with low DLCO and HIV1+ smokers with low DLCO demonstrates that the upregulation of the MMP-9 by AM in HIV+ smokers is likely derived, at least in part, by AM expression of IL-23 working in concert with T lymphocytes to induce AM to express MMP-9, a known contributor to the pathogenesis of emphysema [22]. The gene discussed is MMP9; the disease is pulmonary emphysema.