NKG2D Ligand 2 (N2DL2) is a member of a family of cell-surface proteins. N2DL2 function as ligands for human cytomegalovirus glycoprotein UL16. N2DL2 is anchored to the membrane via a GPI-linkage. N2DL2 is bind to human NKG2D, an activating receptor expressed on NK cells, NKT cells, T cells. Engagement of NKG2D results in the activation of cytolytic activity and cytokine production by these effects cells. The ULBPs are expressed on some tumor cells and have been implicated in tumor surveillance.