NFKB1 and breast cancer: In cervical cancer cells, Notch1 activates NF-kB via IKKα, which migrates to the nucleus in a Notch-dependent fashion (58); similarly, nuclear IKKα mediates the effect of Notch1 in ER+ breast cancer cells, whereby Notch1 activates ERα-dependent transcription in an IKKα-dependent fashion in the absence of estrogen (59).