This gene encodes a type II transmembrane glycoprotein that is the highly polymorphic Kell blood group antigen. The Kell glycoprotein links via a single disulfide bond to the XK membrane protein that carries the Kx antigen. The encoded protein contains sequence and structural similarity to members of the neprilysin (M13) family of zinc endopeptidases. [provided by RefSeq, Jul 2008].