Lymphotoxin-alpha (LTA), a member of the tumor necrosis factor (TNF) family of cytokines, was initially isolated on the basis of an anti-tumor activity. LTA plays a key role in communication between lymphocytes and stromal cells, thereby eliciting cytotoxic effects on cancer cells. It induces the expression of vascular cell-adhesion molecule 1 (VCAM1) on vascular endothelial cells and recruits natural killer (NK) cells to parenchymal organs and tumor lesions.