CD8A and hepatocellular carcinoma: Through the evaluated correlation between RRM2 and 24 immune cell subsets in HCC, we found that RRM2 has a positive correlation with Th2 cells, T helper cells, and T follicular helper (TFH) cells; On the other hand, RRM2 has a negative relationship with Neutrophils, DC, CD8 T cells, and cytotoxic cells (Figure 6A).