Aberration in NFkB–IkB Binding May Cause Two States of NFkB Activity

NFkB activation is involved in cell survival and aberration of NFkB signalling is found in cancer. IkB is an inhibitor that sequesters NFkB in the cytoplasm. By mathematical modelling, we predict that under an aberrant condition in which IkB does not bind to NFkB, there exist two states of NFkB activity: a constitutive activity state for any positive value of the stimulus and a zero activity state for no stimulus. Further, under the assumption that NIK can be activated by TAB1–pTAK1, we predict that TAB1 has a role in the basal activity of NFkB. Thus, we predict the importance of TAB1 and IkB in NFkB activation. Our prediction may have implication for cell survival and cancer.