背景资料：Sialic acid-binding Ig-like lectin 9 is a protein that in humans is encoded by the SIGLEC9 gene. Putative adhesion molecule that mediates sialic-acid dependent binding to cells. Preferentially binds to alpha-2,3- or 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. Expressed by peripheral blood leukocytes (neutrophils and monocytes but not eosinophils).