CDH5 and swine influenza: Cdh5-CreERT2; ROSA26LSL-tdTomato (Atf3EC-WT, n=4) and Cdh5-CreERT2; ROSA26LSL-tdTomato; Atf3lox/lox (Atf3EC-KO, n=3) adult mice received 200 mg/kg tamoxifen by oral gavage 2 weeks before H1N1 influenza injury.