has not been previously described. Tgfb2 null mice have dilated conducting airways and collapsed terminal and respiratory bronchioles61, and loss-of-function mutations in TGFB2 have been associated with Loeys-Dietz syndrome, a disorder of connective tissue showing phenotypic overlap with Marfan syndrome, and has rarely been associated with emphysema62. TGF-β2 is also the predominant isoform present in airway tissue in severe asthma63,64; it is secreted in airway epithelial cells in response to injury or inflammatory cytokines (e.g. IL-13) and appears to play a major role in airway inflammation and remodeling 65–68.
