Fc ? receptor IIIa (Fc?RIIIa), also known as CD16a, is an activating receptor for IgG with roles in antibody-dependent cell cytotoxicity (ADCC).{66271,66272} It is expressed primarily in natural killer (NK) cells, but also in macrophages and non-classical monocytes.{66272,66273} Fc?RIIIa is composed of an extracellular domain which contains five N-glycosylation sites, a transmembrane helix, and a cytoplasmic tail.{66272} Upon binding of IgG, Fc?RIIIa engages one of two signaling chains, CD3? or Fc?RI?, which is phosphorylated by the Src family kinase LCK and induces intracellular signaling and neutrophil activation.{66271} Fc?RIIIa signaling is positively correlated with disease progression and pathogenic lung inflammation in patients with COVID-19.{66273} Mutations in FCGR3A, the gene encoding Fc?RIIIa, are positively correlated with increased risk of colorectal carcinoma.{66274} Cayman’s Fc?RIIIa/CD16a Polyclonal Antibody can be used for ELISA and immunohistochemistry-paraffin (IHC-P) applications.