The previously reported interaction between PXR and p5324, together with the anti-apoptotic20 and proliferation-promoting21 properties of PXR, prompted us to determine the effects of PXR on p53 function in colon cancer by utilizing human colorectal carcinoma HCT116 and RKO (isogenic pair: p53+/+ and p53−/−) and human colorectal adenocarcinoma LS180 cell lines, with or without ectopic expression of lentiviral FLAG-tagged empty vector (EV) or FLAG-tagged human PXR (FLAG-hPXR or PXR). The gene discussed is NR1I2; the disease is malignant colon neoplasm.