CHUK and breast cancer: Western blotting showed that with increasing concentrations of CXCL1, the expression of IKKα (IκB kinase α) and IKKβ and their phosphorylated form p-IKKα/β was upregulated in breast cancer cells, which induced dissociation of IκBα from p65 and led to p65 phosphorylation (Fig. 5a).