Fc-mediated antibody effector functions play an important role in the humoral immune response and form a necessary link between innate and adaptive immunity. The constant (Fc) region is the tail portion of an antibody that interacts with other components of the immune system, such as immune cells and complement proteins. Well-known functions include opsonization, antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), and complement activation.