Trastuzumab and 17-AAG mediate recruitment of different E3 ubiquitin ligases, casitas B-lineage lymphoma (Cbl) and CHIP respectively, to ERBB2 with a synergistic effect on reducing proliferation and promoting apoptosis.[27, 28] Clinical trials are currently under-way evaluating 17-AAG in BC. The gene discussed is ERBB2; the disease is breast cancer.