In our system, although details of the mechanism still remain undetermined, it can be suggested that after CCR2-CCL2 axis-mediated migration into tumor tissues, CCL2 in the tumor microenvironment may strengthen WT1 epitope-responsive cytocidal activity against LK79 cells mediated by infused double-transfected effector CD8+ T cells in vivo. Here, CCR2 is linked to neoplasm.