Immunoregulatory receptor which inhibits the T-cell response (PubMed:24691993). May promote differentiation of embryonic stem cells, by inhibiting BMP4 signaling (By similarity). May stimulate MMP14-mediated MMP2 activation (PubMed:20666777). Expressed in spleen. Detected on a number of myeloid cells including CD11b monocytes, CD66b+ neutrophils, at low levels on CD4+ and CD8+ T-cells, and in a subset of NK cells. Not detected on B cells (at protein level). Expressed at high levels in placenta, spleen, plasma blood leukocytes, and lung. Expressed at moderate levels in lymph node, bone marrow, fat, uterus, and trachea. Has low expression levels in other tissues. At the cell surface, may be cleaved by MMP14. N-glycosylated. Truncated C-terminus. Contaminating sequence. Sequence of unknown origin in the N-terminal part. Extended N-terminus.