HNF4A and hepatocellular carcinoma: In contrast to this predicted result, experimental data on HepG2 (human hepatocellular carcinoma) cells revealed that HNF4α and some of its target genes (including RXR) were instead downregulated, which led the authors to propose an inhibitory effect of quercetin on HNF4α-mediated signaling and, therefore, on RXR.