RRM2 and hepatocellular carcinoma: The clinical proteomic analysis revealed that both TK1: S13 and RRM2: S20 were significantly overexpressed in tumors in comparison to normal adjacent tissues (NAT) (Figure 6d and Figure S2b), with higher phosphorylation levels closely associated with poor prognosis in HBV-associated HCC (Figure 6e and Figure S2c).