CD4 and hepatocellular carcinoma: As shown in Fig. 3E, the proportion of CD4+IL-17+ Th17 cells was significantly higher in the advanced-stage (III–IV) HCC groups of various tumor sizes than in the control group; moreover, the proportion of CD4+IL-17+ Th17 cells was significantly higher in the large tumor size HCC group than in the small tumor size HCC group.