NFKB1 and Sepsis: When compared to WT-CLP mice, Xid-CLP mice the phosphorylation of IKKα/β at Ser176/180 and IκBα at Ser32/36 was significantly reduced, indicating that the degree of activation of NF-κB caused by sepsis in the heart was significantly lower in Xid-mice than in WT-mice (Figures 5C,D).