***INDEFINITE BACKORDER*** Epidermal growth factor receptor (EGFR) is a receptor for EGF and for various members of the EGF family such as TGF-alpha, amphiregulin, betacellulin, heparin-binding EGF-like growth factor, GP30 and vaccinia virus growth factor. EGFR is involved in the control of cell growth and differentation. Binding of EGF to the receptor leads to dimerization, internalization of the EGF-receptor complex, induction of the tyrosine kinase activity, stimulation of cell DNA synthesis and cell proliferation. EGFRvIII has an 801-bp in-frame deletion resulting in a shorter extracellular domain (aa 6-273 are deleted) with generation of a glycine residue at the fusion point. EGFRvIII is tumor specific and is not expressed in normal human tissues. Defects in EGFR are associated with lung cancer.