The cell surface receptor for the Epidermal growth factor is a 170kD cell surface glycoporotein endowed with tyrosine kinase activity. In addition to the Epidermal growth factor several additional ligands have been reported to interact with this receptor among which TGF -cellulin, heparin binding-EGF and amphiregulin. Upon ligand binding the receptor becomes tyrosine autophosphorylated and binds adaptor molecules such as Shc leading to the activation of several distinct signalling pathways. Among these one of the best known is the Ras/MAP kinases pathway. The antibody to the EGF-R is useful for a variety of studies such as analysis of the distribution and expression by western blotting and immunoprecipitation.