The epidermal growth factor receptor (EGFR) is overexpressed in a variety of human epithelial tumors, often as a consequence of gene amplification. Tumors with EGFR gene amplification frequently contain EGFR gene rearrangements, with the most common extracellular domain mutation being EGFRvIII. This mutation leads to a deletion of exons 2-7 of the EGFR gene and renders the mutant receptor incapable of binding any known ligand. EGFRVIII Protein, Human, Recombinant (His & Avi), FITC-Labeled is expressed in HEK293 mammalian cells with C-His-Avi tag. The predicted molecular weight is 41.6 kDa and the accession number is NP_001333870.1.