CTTN and breast cancer: We hypothesized that this could be due to the down-regulation of nuclear factor kappa beta (NF-κB), as Hill et al. elucidated that inhibition of p65 Rel A subunit of NF-κB by IκKinase-2 led to a significant suppression of cortactin mRNA transcription in breast cancer MCF7F-B5 cells [24].