TNF and malignant colon neoplasm: Vγ9Vδ2 T cells that were stimulated by zoledronate and exposed to colon cancer stem cells are induced to proliferate and secrete cytokines (TNF-α and IFN-γ), cytotoxic and apoptotic molecules [TNF-related apoptosis-inducing ligand (TRAIL) and BLT esterase], resulting in the capability of killing and lysing colon tumor cells (20).