Additionally, ablation of IL-21R had no effect on total CD4+ T cells (Fig. 4G and Fig. S8A), although the numbers of HCC-infiltrating Th1, Th17 and Treg cells increased in the absence of IL-21R (Fig. S8B-E), while having little effect on liver B cells (Fig. S9A). Here, CD4 is linked to hepatocellular carcinoma.