Figure 2.

Klf5 is not required for K-Ras^G12D-mediated lung tumorigenesis in mice. K-Ras^G12D;Klf5^+/+ controls (n = 6) and K-Ras^G12D;Klf5^fl/fl experimental (n = 5) mice were intubated with a Cre recombinase adenovirus at six weeks of age. Mice were sacrificed 8 to 16 weeks postinfection, at which point their lungs were inflation fixed and embedded in paraffin. A: The number of lung adenomas (≥0.4 mm) and adenocarcinomas (>1 mm) per mouse were enumerated histopathologically, summed, and represented as tumor number per mouse. The mean tumor number in each genotype is denoted with a straight line. B: Representative images of immunohistochemical detection of Klf5 expression in the airways, alveolar hyperplasia (AH; arrowheads), adenomas, and adenocarcinomas of K-Ras^G12D;Klf5^+/+ and K-Ras^G12D;Klf5^fl/fl mice are shown. Klf5 positive cells are dark brown in contrast to Klf5 negative cells and have been magnified to show their histological appearance (black boxes). Original magnification ×10. Scale bar = 100 μm.