NFKB1 and breast carcinoma: In another study, it was reported that the human breast carcinoma cells, MCF-7, when incubated with physiologic concentrations of estrogen (0.02 nM) for a period of 48 h demonstrated an increase in the expression of MnSOD mRNA, and the upregulation of MnSOD was linked to MAPK and nuclear factor kappa (NFκB) signaling pathways [31].