Cell surface receptor that modulates signaling cascades and mediates tyrosine phosphorylation of target MAP kinases. Interacts with PTPN6 and PTPN11. Ligand binding leads to internalization. Detected in normal myeloid cells and in acute myeloid leukemia cells. Detected in neutrophils, eosinophils, monocytes and dendritic cells. Detected in spleen macrophage-rich red pulp and in lymph node (at protein level). Detected in peripheral blood leukocytes, dendritic cells, bone marrow, monocytes, mononuclear leukocytes and macrophages. Down-regulated in activated leukocytes recruited to a site of inflammation. Contains 1 copy of a cytoplasmic motif that is referred to as the immunoreceptor tyrosine-based inhibitor motif (ITIM). This motif is involved in modulation of cellular responses. The phosphorylated ITIM motif can bind the SH2 domain of several SH2-containing phosphatases. Highly N-glycosylated. Glycosylation varies between cell types. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay.