CASP4 and cystic fibrosis: Abundance of both pro-caspase-1 and auto-cleaved active caspase-1 (p20) was higher in SI/R-primed CF compared to controls (Fig. 4b) but for both caspase-4/5 and caspase-8 (alternative inflammasome pathway), expression levels and proteolytic auto-activation were comparable in both groups (Fig. 4c, d).