MKI67 and infection: Tracheal rudiments were infected with Ad-GFP, Ad-STK11WT, or Ad-STK11KD viruses and cultured for 5 days (Fig. 4a): we found that the proportions of Ki67+ epithelial cells were significantly decreased in the Shh-Stk11 tracheal rudiments with Ad-STK11WT infection at post-culture day 5 (Fig. 4b, c).