On the other hand, the cell can use other receptor networks, i.e., IGF-IR to activate the PI3K/Akt survival pathway. Trastuzumab has been shown to block ligand-independent association between HER2 and HER3 whereas pertuzumab, an antibody that recognizes an epitope in heterodimerization website II of HER2, blocks ligand-induced HER2-HER3 dimerization (43). Continue Reading