High affinity immunoglobulin gamma Fc receptor I (FCGR1A) is a protein that in humans is encoded by the FCGR1A gene. Also, This protein is known as CD64, belongs to the immunoglobulin superfamily. It is a high-affinity Fc-gamma receptor. They are playing a role in both innate and adaptive immune responses. They have been shown to interact with FCAR. The FcgRI binds the Fc portion of IgG and causes activation of the host cell via an intercellular ITAM motif.