Background：CD335, also known as NKp46, is a single-pass type I membrane protein of 46 kD. It belongs to the natural cytotoxicity receptor （NCR） family and contains two Ig-like （immunoglobulin-like） domains. It's expression is restricted to NK cells and a subset of NKT cells; it's not expressed in CD1d-restricted NKT cells. CD335 is a receptor for viral hemagglutinins and heparan sulfate proteoglycans and is involved in NK cell activation.
