Fig. 1

RRM2 is highly expressed in liver cancer. a The 180 ferroptosis-related factors that were downregulated were identified by TMT, RNA-seq and DNase-seq. b RRM2 was identified as the most significantly upregulated secretory or membrane-bound protein in liver cancer via data mining using the TCGA database. c Scatter plot for serum RRM2 in healthy individuals and patients with hepatitis A, hepatitis B, hepatitis C, lung cancer, gastric cancer, breast cancer, colorectal cancer or liver cancer. d RRM2 expression in the sera from healthy individuals and liver cancer patients, as was evaluated by immunoblotting. e TMA of RRM2 in liver cancer and normal liver tissues. Representative IHC images of TMA stained with anti-RRM2 antibodies are shown. Data were analyzed using a chi-square test. f The UALCAN database was used to analyze alterations in RRM2 expression between liver cancer (n = 371) and normal liver (n = 50) tissues. g Kaplan–Meier survival plots of RRM2 were obtained from the KM plotter database. h RRM2 was highly expressed in SMMC-7721 and HepG2 cell. RRM2 expression was measured by immunoblotting with anti-RRM2 antibodies in established hepatocyte (HL-7702) and liver cancer cell lines, as indicated. The IB data are representative images from three biological replicates. **P < 0.01 indicates statistical significance. Data in c were analyzed using a one-way ANOVA test. Data in e were analyzed using a chi-square test. Data in f were analyzed using Student’s t test. Data in g were analyzed using log rank analysis