Recombinant human IgG antibodies recognizing distinct extracellular domains of EGF receptor exhibit different degrees of growth inhibitory effects on human A431 cancer cells

► Four scFv antibodies against human EGFR were converted to humanized IgGs (hIgGs). ► Four hIgG antibodies recognized 4 different sites (epitopes) in 3 different domains of EGFR, respectively. ► Two of those hIgGs inhibited the auto-phosphorylation of EGFR and growth of A431 cancer cells. ► One of those two hIgGs binds to a site outside the ligand-binding domain of EGFR.