Anti-EGFR In Vivo Antibody - Low Endotoxin (EGFR.1) recognizes the (Mr 170 kDa) extracellular domain of the epidermal growth factor receptor on many cell surfaces. The EGFR mediates the initial response of cells to EGF. It has an extracellular region which binds EGF and an intracellular region which exhibits tyrosine kinase activity. The receptor phosphorylates a number of protein substrates in addition to mediating autophosphorylation