CD4 and neoplasm: The frequency of CD4+ Foxp3+ Tregs was higher in control, tumor bearing BALB/c mice, accounting for approximately 35% of total splenocytes, but there was a significant decrease of Tregs in the combination group as compared with the other treatment groups (3.70 ± 0.23% in combination group vs. 13.88 ± 0.75% in lycorine hydrochloride group and 10.98 ± 0.38% in anti-mouse CTLA-4 group) (Figure 5A and 5B).