TWEAK belongs to the TNF family of ligands, and also known as TNFRSF12A through TWEAK receptor signaling. TWEAK wildly expresses in a variety of tissues, including the adult heart, pancreas, skeletal muscle, small intestine, spleen and peripheral blood lymphocytes. TWEAK has the ability to trigger activation and chemokine secretion of NF-κB, and to apply an apoptotic activity in certain cells, such as HT-29 human cultured adenocarcinoma cells feeding with IFN-γ. TWEAK also promotes proliferation and migration of endothelial cells.