TNFSF18, also known as GITRL, belongs to the tumor necrosis factor(TNF) ligand family. This cytokine is a ligand for receptor TNFRSF18/AITR/GITR. It is Important for interactions between activated T-lymphocytes and endothelial cells and may modulate T-lymphocyte survival in peripheral tissues. This cytokine is also found to be expressed in endothelial cells, and is thought to be important for interaction between T lymphocytes and endothelial cells. Recombinant human TNFSF18 protein was expressed in E.coli and purified by conventional chromatography, after refolding of the isolated inclusion bodies in a renaturation buffer.