TNF and inflammatory bowel disease: In addition to Vδ 1 T cells and Vδ 2 T cells, Kadivar et al. have defined and characterized a novel subtype of human CD8αβ+ γδ T cells that were enriched in the intestinal tract of patients with active IBD and produced cytotoxic mediators, such as IFN-γ and TNF-α, suggesting a role in IBD (88).