CTLA4 and neoplasm: As shown in Fig 3A, antibody treatment with anti-CTLA-4 (p<0.02), anti-BTLA (p<0.01), anti- PD-L1 (p<0.01), anti- Lag-3 (p<0.001) and anti- PD-1 antibodies (p<0.02) led to a modest but a significant delay in tumor growth in MC-38 bearing mice (p values compared to mice that received isotype control antibody).