EPCAM and pulmonary emphysema: To determine whether fetal lung progenitors can be engrafted into mouse models of emphysema, and whether these progenitor cells have the potential to reconstruct alveolar walls, we first intratracheally transplanted E15.5 CAG-EGFP total lung cells or sorted Epcam+ cells into elastase-treated mice, however, it did not yield efficient engraftment (Supplementary Fig. S1A, S1B).