ABCB1 and cancer: Thus, the intestinal ABCB1 mRNA levels were found to be associated with polymorphisms in ABCB1 and NFKB1 (encoding the p50 subunit of the transcription factor nuclear factor κB (NFκB)) in morphologically normal tissue from adenoma case, whereas no association was found in either dysplastic tissue from adenoma cases or in morphologically normal or cancer tissue from CRC cases [30].