ChEBI: Erlotinib is a quinazoline compound having a (3-ethynylphenyl)amino group at the 4-position and two 2-methoxyethoxy groups at the 6- and 7-positions. It has a role as an antineoplastic agent, a protein kinase inhibitor and an epidermal growth factor receptor antagonist. It is a member of quinazolines, a terminal acetylenic compound, an aromatic ether and a secondary amino compound.NCI Thesaurus (NCIt): Erlotinib is a quinazoline derivative with antineoplastic properties. Competing with adenosine triphosphate, erlotinib reversibly binds to the intracellular catalytic domain of epidermal growth factor receptor (EGFR) tyrosine kinase, thereby reversibly inhibiting EGFR phosphorylation and blocking the signal transduction events and tumorigenic effects associated with EGFR activation.