TNF and gangrene: The combined effects of the TNFα secreted by Vγ9δ2 cells, together with the IL-4 produced by Vδ1+ T cells increases vascular cell adhesion molecule 1 (VCAM-1) expression on endothelial cells in digital arteries and VCAM-1-mediated adhesion of TF-1+ monocytes to the endothelium could then activate local thrombosis and gangrene (45).