EGFR and carcinoma: The discovery that the dysregulated activation of EGFR is fundamentally important in cell transformation was made when the complete amino acid sequence encoding the human EGFR, which was derived in 1984 from cDNA clones extracted from placental and A431 carcinoma cells [11], revealed a high degree of homology with the v-erbB mRNA retroviral oncogene of the avian erythroblastosis virus, which encodes a truncated homologue of the human EGFR [12].