ERBB2 and neoplasm: Some mAbs are directed against growth factor receptors with high levels of expression in tumours cells and inhibit tumour growth by blocking the binding of growth factor to its receptor (e.g., anti-EGFR mAbs cetuximab and panitumumab), or by inhibiting receptor dimerization (e.g., anti-HER-2 mAb pertuzumab), consequently inhibiting the downstream cell signalling pathways.