NR4A1 and hepatocellular carcinoma: In present study, we found that four genes, including JUN (the oncogene encoding c-Jun protein), GADD45G, NR4A1 and DUSP6,which associated with MAPK signaling pathways, were downregulated in patients with HBV-related HCC tissues with BCLC 0 staging than in non-tumor tissues via analysis of DAVID online tools (Fig 5A and S5 Table).Previous study from Endo M et al. showed that no copy number gain of JUN was seen in primary HCC tumors.