Respiratory parameters and body weight in non-infected CF mice and their non-CF littermates (left panels: B6, CftrMHH ; right panels: WT, CftrKO ). At the day of assessment young mice were younger than 100 days and old mice elder than 179 days. The boxplots show the median, inner quartiles and range of the parameters and are clear for wildtype mice (B6, WT) and are shaded in grey for CF mice (CftrMHH, CftrKO). CF mice and non-CF littermates were compared in their lung function and body weight by Mann-Whitney rank tests (* = p < 0, 05; ** = p < 0, 01; *** = p < 0, 001). The number of investigated animals per group (n) is indicated in Figure 1E. Figure 1A shows that the tidal volume is very similar for all genotypes. The respiratory rate is higher (Figure 1B) and the time for one breath is shorter in CF mice (Figure 1C).