HIF also causes the upregulation of P-gp, multidrug-resistance-associated proteins (MRPs), lung resistance protein (LRP), and ABC subfamily G member 2 (ABCG2), which increase drug efflux and reduce intracellular drug concentrations, thereby facilitating sorafenib resistance in HCC [116]. This evidence concerns the gene ABCG2 and hepatocellular carcinoma.