MAPK3 and pulmonary emphysema: Histological analysis revealed that the lungs of Pdgfrb-Cre/ERT2+/−;Gnaqfl/fl;Gna11−/− mice treated with tamoxifen had increased airspace size compared with Gna11−/− controls (mean linear intercept distance 52.5 μm in Pdgfrb-Cre/ERT2+/−;Gnaqfl/fl;Gna11−/− mice compared with 39.3 μm in Gna11−/− controls, P=0.03; Fig. 6D,E), suggestive of emphysema.