The invention relates to new polypeptide in isolated form belonging to a subfamily of the human Immunoglobulin Superfamily, which polypeptide shows at least 70% sequence homology with the amino acid sequence of the murine Confluency Regulated Adhesion Molecules 1 or 2 (CRAM-1 or CRAM-2) as depicted in Fig 3 upper and second row, respectively, and antibodies thereto as well as their use in treatment of inflammation and tumors.