(A) A20-bearing BALB/c mice (n = 4/group) were administered with 100 μg of anti-mCD20 or hIgG on day 15 and day 20. CD4+ T cell-depleting Ab (GK1.5, 200 μg/mouse) was administered twice a week, starting on day 14. (B) A20 bearing WT BALB/c mice (n = 5/group) were i.t. administered respectively with 100 μg of hIgG and 100 μg of hamster IgG, 100 μg of anti-mCD20 and 100 μg of hamster IgG, 100 μg of anti-CTLA-4 Ab and 100 μg of hIgG, or 100 μg of anti-mCD20 combined with 100 μg of anti-CTLA-4 Ab on day 15. (C) A20-bearing WT BALB/c mice (n = 5/group) were administrated i.t. as in A, but with an extra group of anti-CTLA-4 i.p. injection (Anti-CD20 + anti-CTLA-4 i.p.). (D) About 60 days after the tumor rejection in anti-mCD20 combing anti-CTLA-4 Ab treated mice, 5×106 A20 cells were injected for tumor rechallenging assay. Naïve WT BALB/c mice were used as control. The mean ± SEM values are shown.