CTLA4 and neoplasm: Preclinical studies showed that subcutaneous injection of GVAX plus CTLA-4 blockade synergistically promoted tumor eradication in the B16 mouse melanoma model (response rate 80 versus 16% with GVAX alone) (79) due to an increase in CD8+ T cells and in effector T cell/Treg ratio in the tumor (80).