NFKBIA and ischemia: Also, it was shown before, that NF-κB activation in the liver is greatly reduced in aged mice compared to young mice after hepatic ischemia/reperfusion injury due to the decreased proteasome subunit, non-ATPase 4 expression preventing recruitment of phosphorylated and ubiquitinylated IκBα to the proteasome, resulting in a defect in NF-κB activation (29, 53).