AG-494 (Tyrphostin AG 494) is a potent and selective EGFR tyrosine kinase inhibitor (IC 50 =0.7 μM). AG-494 inhibits the autophosphorylation of EGFR, ErbB2, HER1-2 and PDGF-R with IC 50 s 1.1, 39, 45 and 6 μM, respectively. AG-494 blocks Cdk2 activation and inhibits EGF-dependent DNA synthesis AG-494 (Tyrphostin AG 494) is a potent and selective EGFR tyrosine kinase inhibitor (IC 50 =0.7 μM). AG-494 inhibits the autophosphorylation of EGFR, ErbB2, HER1-2 and PDGF-R with IC 50 s 1.1, 39, 45 and 6 μM, respectively. AG-494 blocks Cdk2 activation and inhibits EGF-dependent DNA synthesis