NFKB1 and neoplasm: In the present study, we demonstrate that (a) NIBP mRNA and protein were highly expressed in many cancer cell lines and tumor tissues; (b) NIBP knockdown inhibited the proliferation, migration and colony formation of breast and colon cancer cell lines in vitro as well as the tumor formation in vivo; (c) NIBP overexpression promoted cell survival, migration and colony formation; (d) NIBP maintains high levels of constitutive NFκB activity and enhances cytokine-induced NFκB activation through the classical IKK2/IκBα/p65 pathway.