CLEC4M

C-type lectin domain family 4 member M is a protein that in humans is encoded by the "CLEC4M" gene. CLEC4M has also been designated as CD299 (cluster of differentiation 299).
This gene encodes L-SIGN (liver/lymph node-specific intracellular adhesion molecules-3 grabbing non-integrin), a type II integral membrane protein that is 77% identical to CD209 antigen, an HIV gp120-binding protein. This protein, like CD209, efficiently binds both intercellular adhesion molecule 3 (ICAM3) and HIV-1 gp120, and enhances HIV-1 infection of T cells. This gene is mapped to 19p13.3, in a cluster with the CD209 and CD23/FCER2 genes. Multiple alternatively spliced transcript variants have been found for this gene, but the biological validity of some variants has not been determined.