Treatment of nude mice bearing 818-4 with daily intraperitoneal injections of normal saline (□), mAb 425 (○), cytokines (▵), cytokines plus mAb 425 (⋄), and cytokines plus F(ab′)2 425 (▿) for the indicated periods. Error bars represent the standard errors and, if complete remission occurred under treatment, numbers of cases per group are assigned as fractions.