INTRODUCTIONEpidermal-growth-factor receptor(EGFR) is apolypeptide with 1186 amino acids,which binds toEGF family growth factors.Two major naturalligands in the family interact with EGFR:one isEGF,the other is transforming growth factor-α(TGF-α).When EGF or TGF-α,binds to EGFR,tyrosine kinase activity is induced which in turntriggers a series of events regulating the cellgrowth.The importance of EGFR in growthregulating pathways was confirmed by the fact that INTRODUCTIONEpidermal-growth-factor receptor(EGFR) is apolypeptide with 1186 amino acids,which binds toEGF family growth factors.Two major naturalligands in the family interact with EGFR:one isEGF,the other is transforming growth factor-α(TGF-α). When EGF or TGF-α, binds to EGFR, tyrosine kinase activity is induced which in turntriggers a series of events regulating the cell growth. The importance of EGFR in growthregulating pathways was confirmed by the fact that