FcγRIII, synonymously also referred to CD16, is a type III Fcγ receptor which has other two identified members: a high-affinity receptor FcγRI (CD64) and a low-affinity one FcγRII (CD32). This transmembrane protein, FcγRIII, contains two extracellular immunoglobulin (Ig)-like domains with low-affinity for IgG. It is responsible for antibody-dependent cellular cytotoxicity. FcγRIII is expressed on large granular lymphocytes of both nature killer (NK)- and T-cell types. There are two different isoforms of it in humans named FcγRIIIa and FcγRIIIb, sharing 96% sequence identity in extracellular Ig binding regions. FcγRIIIa is a transmembrane receptor found on macrophages, mast and NK cells. FcγRIIIb is expressed exclusively on neutrophils and functions as the only Fc receptor anchored via a glycosyl-phosphatidylinositol (GPI) linker to the cell membrane. EGFR (Epidermal growth factor receptor, also known as ErbB1, ErbB or HER1) is a type I transmembrane glycoprotein involved in normal growth. It belongs to a member of the receptor tyrosine kinase superfamily and makes up the ErbB family with HER2/neu (ErbB-2), HER3 (ErbB-3) and HER4 (ErbB-4). The EGFR gene is encoded on chromosome 7p11.2 and activated by binding to specific protein ligands, such as epidermal growth factor (EGF) and transforming growth factor α (TGF-α). Ligand binding induces EGFR dimerizations resulting in protein-tyrosine kinase activation and cellular signaling. EGFR also plays a role in carcinogenic responses and the increased expression of it in most cases is predictive of tumor progression.