However, 25–30% higher levels of total protein were observed in BAL of G-CSF−/− mice after infection (963 μg/ml in WT vs. 1207 μg/ml in G-CSF−/− mice; data not shown), suggesting partial loss of bronchoalveolar-epithelial integrity in mice deficient in G-CSF. This evidence concerns the gene CSF3 and infection.