RRM2 and hepatocellular carcinoma: Survival analysis revealed that patients with high RRM2 expression had a shorter OS, with an HR of 2.01 and a median survival of 38.3 months, than patients with low RRM2 gene expression, who had a median survival of 71 months (Fig. 2B), indicating the association of RRM2 expression with poorer prognosis in HCC patients.