We discovered that the protein inhibitor of activated STAT (PIAS)y, which is induced by reactive oxygen species (ROS) and participates in the SUMOylation of NF-κB essential modulator (NEMO) upon genotoxic stress (Mabb and Wuerzberger-Davis, 2006), is upregulated in CF epithelia in response to oxidative stress and then mediates SUMOylation of TG2 (Luciani et al., 2009). This evidence concerns the gene PIAS4 and cystic fibrosis.