Figure 3: (a) Expression of mRNA for IL-33, relative to HPRT, in airway wall tissue from the acute exacerbation and control groups (mean ± SEM). (b) Intensity of immunoreactivity for IL-33 in the airway epithelium (median ± interquartile range). Significant differences relative to the naïve group are shown as and those relative to the acute exacerbation group are shown as ( samples per group).