CD16a is a transmembrane protein that acts as a receptor for the Fc portion of IgG antibodies. It is expressed on natural killer cells, monocytes, macrophages, dendritic cells, and some T cells. CD16a is also known as FCGR3A or FcγRIIIa. CD16a is involved in antibody dependent cellular cytotoxicity (ADCC) by binding to antibodies that target infected or malignant cells.