Acquired Resistance to Small Molecule ErbB2 Tyrosine Kinase Inhibitors

Proposed mechanisms of acquired resistance: crosstalk with insulin-like growth factor receptor I; PTEN mutation or loss of heterozygosity (LOH); depression of FOXO3a with increased ER transcriptional activity; increased membrane localization of ErbB3; extracellular domain (extracellular domain) shedding resulting in p95.