The ability of T cells to migrate and adhere is critical for an effective immune response. Migration is induced in response to chemoattractant gradients provided by the secretion of chemokines. The migration of T cells along the inflamed vascular endothelium involves the processes of tethering and rolling, which are mediated by selectins and mucins. Their actions cause T cells to slow the pace of migration, allowing interaction with the endothelium and sampling of the local environment for stimulating factors. Under inflammatory conditions, T cells will bind to endothelial surfaces and exit into target tissues, a process which is dependent on integrin-mediated adhesion to the endothelium. LFA-1/CD18 is the main receptor used by T cells for adhesion via the ICAM family of ligands.