C2 and hepatocellular carcinoma: In the GSE14520 cohort, significantly higher proportions of resting mast cells, follicular helper T cells, and resting CD4 memory T cells were found in HCC patients with higher C2 expression, while significantly higher proportions of macrophage M0 cells, activated mast cells, and plasma cells were found at HCC patients with lower C2 expression (all p < 0.05, Figure 4(b)).