CD4 and hepatocellular carcinoma: Patients with either deletion spanning pre-S2 gene segment or high percentage of pre-S2 plus pre-S1 + pre-S2 deletion had a significantly higher density of CD4+CD25+ cells in HCC tissues than those without (mean ± SEM, 12.81 ± 0.66 versus 3.07 ± 0.40 cells/mm2, P < 0.0001; 12.73 ± 0.75 versus 5.45 ± 0.97 cells/mm2, P < 0.0001, respectively) (Fig. 3C,D; right graphs).