Receptor for KLRB1 that protects target cells against natural killer cell-mediated lysis (PubMed:20843815, PubMed:16339513). Inhibits osteoclast formation (PubMed:14753741, PubMed:15123656). Inhibits bone resorption (PubMed:14753741). Modulates the release of interferon-gamma (PubMed:15104121). Binds high molecular weight sulfated glycosaminoglycans (PubMed:15123656). Homodimer; disulfide-linked. Detected in peripheral blood leukocytes, osteoblasts, lymph node, thymus and spleen. Isoform 1, isoform 2 and isoform 4 are expressed in T- and B-lymphocytes, and at lower levels in NK cells. They are also expressed in B-cell lines and LPS-matured monocyte-derived dendritic cells. Up-regulated by IL1A/interleukin-1 alpha and prostaglandin E2 in cultured osteogenic sarcoma cells. N-glycosylated. LLT1