PTPRC and cystic fibrosis: Immunohistochemistry staining of CD45 to identify leukocytes in lung of infected CF mice at day 1 (Figures 4I-L) revealed a trend towards decreased inflammatory cell recruitment (Figure 4M) and neutrophil elastase (NE) in broncho-alveolar lavage fluid (BALF) (Figure 4N) in PD0325901-treated mice compared to vehicle, though not statistically significant.