EGF-TM7: A novel subfamily of seven-transmembrane-region leukocyte cell-surface molecules

The recent cDNA cloning of three cell-surface molecules has identified a subfamily of leukocyte proteins that are characterized by the presence of tandemly repeated extracellular epidermal growth factor (EGF)-like domains and a seven-transmembrane (Tm7) region. Here, Andrew McKnight and Siamon Gordon review the unusual structural properties of these molecules, their similarities to certain peptidic hormone receptors, and speculate as to their immunological function.