ABCB1 and colorectal cancer: Agarwal et al. [28] showed that PI3K/AKT/IkB kinase (IKK) signaling was abnormally activated in colorectal cancer and upregulated the expression of MDR1 genes and its protein product P-glycoprotein (P-gp) by regulating the transcription factor NF-kB, eventually leading to chemoresistance.