IHC 3+ or HER2 amplification via chromogenic or silver in situ hybridization (ISH) was permitted in this study, but based on breast cancer data, only HER2 FISH positivity (HER2/CEP17 ratio ≥ 2.0) was considered as “HER2-positive” and included in efficacy analyses. This evidence concerns the gene ERBB2 and breast cancer.