– CD160 (also Natural killer cell receptor BY55) is a 27 ‑ 30 kDa member of the Ig superfamily. In human, it is expressed principally on nonmyeloid hematopoietic cells. CD160 antigenis a receptor on immune cells capable to deliver stimulatory or inhibitory signals that regulate cell activation and differentiation. Exists as a GPI-anchored and as a transmembrane form, each likely initiating distinct signaling pathways via phosphoinositol 3-kinase in activated NK cells and via LCK and CD247/CD3 zeta chain in activated T cells.