Ligand for the KLRK1 immunosurveillance receptor. Binding to KLRK1 stimulates cell lysis in vitro. In strain C57BL/6J, strongly expressed in cardiac muscle and skeletal muscle, with lower expression levels in spleen, liver, kidney and thymus. In strain BALB/cJ, weakly expressed in cardiac muscle, spleen, kidney and thymus. Up-regulated in response to infection by murine cytomegalovirus. Belongs to the NKG2D ligand family.