Fragment crystallizable region of immunoglobulin (Fc region) (Fc region)

The Fc region is the constant domain at the C-terminal end of an antibody, formed by dimerization of the antibody heavy chains, which allows interaction with immune effector molecules. While Fab regions determine antigen specificity, the Fc region controls immune system activation via binding to Fc receptors (on immune cells such as macrophages, NK cells, and others) and to complement proteins. Engineering the Fc region in therapeutic antibodies modifies immune effector functions (such as ADCC, ADCP, CDC) and pharmacokinetics. The Fc region is not a disease-associated cellular receptor, enzyme, or biomarker but is an integral structural and functional part of therapeutic antibody drugs[1][2][5][6][7].

Other names

Fragment crystallizable regionFc fragmentFc domain

Effector cell recruitment via Fc receptor binding (ADCC, ADCP) Complement activation (CDC) Extended half-life via neonatal Fc receptor (FcRn) binding