In total, as is shown in Table 5, 17 significant KEGG pathways, such as “cell cycle,” “complement and coagulation cascades,” “AMPK signaling pathway,” and “PPAR signaling pathway,” overlapped in the three HCC cohorts, indicating that C2 may influence the prognosis of HCC by regulation of these 17 overlapped KEGG pathways. Here, PPARA is linked to hepatocellular carcinoma.