protein_function: Cell adhesion molecule that mediates both heterotypiccell-cell contacts via its interaction with CD6, as well ashomotypic cell-cell contacts. Promotes T-cell activation andproliferation via its interactions with CD6 (By similarity).Contributes to the formation and maturation of the immunologicalsynapse via its interactions with CD6 (By similarity). Mediateshomotypic interactions with cells that express ALCAM(PubMed:24740813). Mediates attachment of dendritic cells ontoendothelial cells via homotypic interaction. Inhibits endothelialcell migration and promotes endothelial tube formation viahomotypic interactions (PubMed:23169771). Required for normalorganization of the lymph vessel network (PubMed:23169771).Required for normal hematopoietic stem cell engraftment in thebone marrow (PubMed:24740813). Plays a role in hematopoiesis; required for normal numbers of hematopoietic stem cells in bonemarrow (PubMed:25730656). Promotes in vitro osteoblastproliferation and differentiation (PubMed:25730656). Promotesneurite extension, axon growth and axon guidance; axons growpreferentially on surfaces that contain ALCAM (By similarity).Mediates outgrowth and pathfinding for retinal ganglion cell axons(PubMed:15345243)..
CD166 antigen is a 100-105 kD typeI transmembrane glycoprotein that is a member of the immunoglobulin superfamily of proteins. In humans it is encoded by the ALCAM gene. The gene was mapped to human chromosome 3q13.1-q13.2 by fluorescence in situ hybridization of cDNA probes to metaphase chromosomes. It is also called CD166 (cluster of differentiation 166), MEMD, SC-1,DM-GRASP,BEN in the chicken, and KG-CAM in the rat. It is expressed on activated T cells, activated monocytes, epithelial cells, fibroblasts, neurons, melanoma cells, and also in sweat and sebaceous glands. CD166 protein expression is reported to be upregulated in a cell line deriving from a metastasizing melanoma. CD166 plays an important role in mediating adhesion interactions between thymic epithelial cells and CD6+ cells during intrathymic T cell development. Recently, CD166 has also been used as a potential cancer stem cell marker.