CFTR and cystic fibrosis: Inhibiting TG2 activity by cystamine (and its reduced form cysteamine) or targeting ROS can reduce inflammation in F508del-CFTR airways, both in vivo in F508del-CFTR homozygous mice (CftrF508del mice) and in ex vivo using explanted human polyp biopsies from CF patients (Raia et al., 2005; Luciani et al., 2010).