To investigate mechanisms by which cancer cells progress to a resistant phenotype, we employed a previously established in vitro model of acquired resistance (27,35,37,39,83), the cell line MCF-7TN-R, which is resistant to both death receptors and chemotherapeutic drugs that depend on p38 MAPK and NF-κB signaling (27,37,55,84). Here, NFKB1 is linked to cancer.