The invention provides novel polynucleotides and polypeptides encoded by such polynucleotides and mutants or variants thereof that correspond to a novel human secreted CD84-like polypeptide. These polynucleotides comprise nucleic acid sequences isolated from cDNA library from human spleen (Hyseq clone identification numbers 2938352 (SEQ ID NO: 1)). Other aspects of the invention include vectors containing processes for producing novel human secreted CD84-like polypeptides, and antibodies specific for such polyeptides.