Specifically, in HCC cells, upregulated LCA activates the expression of PXR, which in turn stimulates the expression of its downstream genes (e.g. CYP3A4 and MDR1) to interfere with the metabolism and clearance of toxic compounds (e.g. anti-tumor drugs), ultimately leading to drug resistance in HCC [37–39]. The gene discussed is ABCB1; the disease is hepatocellular carcinoma.