Interrupting the ERBB2-ERBB3 heterodimer using lapatinib (GW572016, GlaxoSmithKline), a potent small-molecule inhibitor of EGFR and ERBB2 tyrosine kinases, leads to proteasomal degradation of BIRC5 and induces apoptosis both in breast cancer cell lines overexpressing ERBB2 and in primary tumors [97]. The gene discussed is ERBB2; the disease is breast carcinoma.