necessary for the expression of LT-α1-β2 on the cell surface as LT-α aids in the movement of LT-β to the cell surface to form LT-α1-β2. In the LT-α mediated signaling pathway, LT-α binds with LT-β to form the membrane-bound LT-α1-β2 complex. Binding of LT-α1-β2 to the LT-β receptor on the target cell can activate various signaling pathways in the effector cell such as the activation of the NF-κB pathway, a major signaling pathway that results in the release of additional pro-inflammatory cytokines essential for the innate response. The binding of lymphotoxin to LT-β receptors is essential for the recruitment of B cells and cytotoxic (CD8+) T cells to specific lymphoid sites to allow the clearing of antigen. Signaling of the LT-β receptors can also induce the differentiation of NK (natural killer) and NK-T cells, which are key players in the innate immune defense and in antiviral responses. Carcinogenic interactions Lymphotoxin has cytotoxic properties that can aid in the destruction of tumor cells and promote the death of cancerous cells. The activation of LT-β receptors causes an up-regulation of adhesion molecules and directs B and T cells to specific sites to destroy tumor cells. Studies using mice with an LT-α knockout found increased tumor growth in the absence of LT-αβ. However, some studies using cancer models have found that a high expression of lymphotoxin can lead to increased growth of tumors and cancerous cell lines. The signaling of the LT-β receptor may induce the inflammatory properties of specific cancerous cell lines, and that the elimination of LT-β receptors may hinder tumor growth and lower inflammation. Mutations in the regulatory factors involved in lymphotoxin signaling may increase the risk of cancer development. One major instance is the continuous initiation of the NF-κB pathway due to an excessive binding of the LT-α1-β2 complex to LT-β receptors, which can lead to specific cancerous conditions including multiple myeloma and melanoma. As excessive inflammation can result in cell damage and a higher risk of the growth of cancer cells, mutations that affect the regulation of LT-α pro-inflammatory signaling pathways can increase the potential for cancer and tumor cell development. See also Lymphotoxin beta receptor Tumor necrosis factor-alpha#Discovery References Further reading External links Cytokines