CCR7 and neoplasm: Given the knowledge that in vitro expanded Vγ9Vδ2 T cells –do not present antigen in the absence of added tumor antigen –, the most rational setup for maximal cytotoxic effector function in ACT would be to use Vγ9Vδ2 T cells that do not express CCR7, e.g. have been expanded for 14 days or more.