RRM2 and liver cancer: The expression of 22 Hub Genes in liver cancer and normal liver tissues was analyzed and it was found that SPP1, AURKA, NQO1, NUSAP1, TOP2A, UBE2C, AFP, GMNN, PTTG1, RRM2, UBE2T, GPC3, SPARCL1 etc. (Fig. 5A), a total of 13 genes, were highly expressed in liver cancer tissues.