p40 mRNA expression in the lung of SP-C/p40 Tg mice. Organs were obtained from 7 weeks old Tg and Wt mice. Cellular RNA (20 µg) was analysed by Northern blotting as described in the Methods section. Lane 1: lung Tg, 2: liver Tg, 3: heart Tg, 4: intestine Tg, 5: kidney Tg, 6: lung Wt, 7: liver Wt, 8: heart Wt, 9: intestine Wt, 10: kidney Wt.