The ABM of Ceresa et al. [40] focused on emphysema progression (excess degradation of collagen) in chronic obstructive pulmonary disease and considered the transition of macrophages between the M1 and M2 phenotypes, secretion of TGF-β from M2 macrophages, recruitment of fibroblasts by TGF-β, fibroblast-mediated collagen deposition, and collagen degradation by MMP9. The gene discussed is TGFB1; the disease is pulmonary emphysema.