NFKB1 and breast cancer: Therefore, apoptotic effects of Fxol in BC cells may be due to the reduction in p65 phosphorylation, and the different apoptotic responses observed in MDA-MB-231 and MCF-7 cells are probably due to the different inhibitory mechanisms involving canonical (p65) and non-canonical (p52, Rel-B) NF-κB signaling pathways.