As a case in point, the humanized antibody trastuzumab (Herceptin), targeting the receptor tyrosine kinase HER2 in breast cancer, improves disease-free survival in HER2+ patients by 52% when administered in the adjuvant setting and prolongs overall survival by 24% for patients with metastatic disease (1,2). This evidence concerns the gene ERBB2 and breast carcinoma.