Putative adhesion molecule that mediates sialic-acid dependent binding to cells. Binds to alpha-2,6-linked sialic acid. The sialic acid recognition site may be masked by cis interactions with sialic acids on the same cell surface. Interacts with LEP. Expressed at high levels in placenta (cyto- and syncytiotrophoblastic cells) and at lower levels in spleen, peripheral blood leukocytes (predominantly B-cells) and small intestine. 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. Should not be confused with SIGLEC5 which has been called CD33L2. Belongs to the immunoglobulin superfamily. SIGLEC (sialic acid binding Ig-like lectin) family. Siglec-6