As is shown in Figure 5, in the TCGA cohort, KEGG pathways, such as “cell cycle,” “ubiquitin-mediated proteolysis,” “complement and coagulation cascades,” “spliceosome,” and “RNA transport,” were most significantly enriched in HCC patients with higher C2 expression compared to HCC patients with lower C2 expression (all p < 0.001, Figure 5(a)). Here, C2 is linked to hepatocellular carcinoma.