Hepatic differentiation occurs in the epithelium of Mgp^−/− lungs. (a) Analysis of albumin and AFP-positive cells in Mgp^−/− lungs (n = 3). (b) Gene expression involved in hepatic, pulmonary, or endothelial differentiation was determined in albumin and AFP–double-positive cells in Mgp^−/− lungs by real-time PCR. Negative cells were used as controls. Data were analyzed by two-sided t test. ***, P < 0.001. Error bars are standard deviation. Data distribution was assumed to be normal, but this was not formally tested. (c) Costaining of albumin (red) and airway progenitor markers Sox9 or Foxp2 (green) in WT (Mgp^+/+) and Mgp^−/− E12.5 lungs (n = 5). (d) Costaining of albumin (red) and type I epithelial cell marker aquaporin 5 (Aqp5), type II epithelial cell marker surfactant protein B (Spb), or CCSP in Mgp^+/+ and Mgp^−/− lungs on P28 (n = 5). (e) Schematic diagram of the differentiation of albumin-positive cells in Mgp^−/− lungs. Bars, 50 µm.