RRM2 and hepatocellular carcinoma: As reported previously, genes for DNA synthesis, cell cycle and ubiquitination, including RRM2, CCNB1, AURKA, NUSAP1, UBE2S, UBE2T, etc. were over-expressed; whereas genes for cell death and liver function, such as Egr1, MT1F and p450 family members, were under-expressed in HCC relative to the ANC tissue.