NFKB1 and cancer: Macrophages have been shown to change their cytokine response to stimulation through a change in the level of NFκB p50 in cells, as a result of signaling through NFκB p50 homodimers rather than conventional NFκB p50:p65 heterodimers [40] and we have demonstrated that NFκB1−/− macrophages do not change their cytokine response in the presence of irradiated cancer cells [18].