CD8A and neoplasm: Thus, when exploring tumor reactivity with selected Vδ1TCR for the development of γδT cell-based immunotherapies (20), the absence of functional reactivity by an introduced Vδ1TCR might not necessarily reflect the absence of binding of the Vδ1TCR to its target but rather the lack of a co-stimulation through, e.g., CD8α or other co-stimulatory molecules.