Complex sentence: An NK cell express CD16 which is a Fc receptor recognizes the Fc portion of an antibody, such as IgG, which has bound to the surface of a pathogen-infected target cell.
Split into simpler sentences: An NK cell express CD16 which is a Fc receptor. This receptor recognizes, and binds to, the Fc portion of an antibody, such as IgG, which has bound to the surface of a pathogen-infected target cell.