As shown in Fig. 5A,B, there was a high positive correlation between the percentage of pre-S2 plus pre-S1 + pre-S2 deletion and the density of CD4+CD25+ cells and Foxp3-expressing cells in HCC tissues (Pearson’s correlation coefficient (r) = 0.6461; P < 0.0001; r = 0.7817, P < 0.0001, respectively). Here, CD4 is linked to hepatocellular carcinoma.