NFKB1 and cancer: In accordance with previous findings showing that NFκB and p53 have opposing effects in cancer cells with antagonistic signaling, crossregulating each other’s activity and suppressing each other’s ability to enhance gene expression, [18] our observation that NFκB phosphorylation is increased by inhibiting p53 (Figure 5C) suggests that p53 acts as an antagonist of NFκB phosphorylation in A549 cells.