Method: To investigate which molecules govern the activation of pro-tumorigenic γδ T cells, we measured the expression of various activating receptors on CD27+ and CD27— γδ T cells from tumour naïve or tumour-bearing mice, as CD27 stratifies IFNγ-producing (CD27+) from IL-17-producing (CD27—) γδ T cells. This evidence concerns the gene CD27 and neoplasm.