Sialic acid-binding immunoglobulin (Ig)-like lectins, or SIGLECs (e.g., CD33 (MIM 159590)), are a family of type 1 transmembrane proteins each having a unique expression pattern, mostly in hemopoietic cells. SIGLEC8 is a member of the CD33-like subgroup of SIGLECs, which are localized to 19q13.3-q13.4 and have 2 conserved cytoplasmic tyrosine-based motifs: an immunoreceptor tyrosine-based inhibitory motif, or ITIM (see MIM 604964), and a motif homologous to one identified in signaling lymphocyte activation molecule (SLAM; MIM 603492) that mediates an association with SLAM-associated protein (SAP; MIM 300490) (summarized by Foussias et al., 2000 [PubMed 11095983]).