γδ T cells show anti-tumor role through producing high levels of IFN-γ, TNF-α, perforins and granzymes when activation; on the other hand, IL23, IL1β and IL6 secreted from tumor cells induced the differentiation of IL-17–producing γδ T cells (γδ17 T cells) to induce vascular endothelial growth factor expression, angiogenesis, proliferation and invasion of the tumor (144). This evidence concerns the gene PRF1 and neoplasm.