In a retrospective study, Dawood et al. showed that patients with HER2+ disease and CNS metastases treated with the recombinant humanised IgG1 monoclonal anti-HER2 antibody trastuzumab had better survival (11.6 months) compared with patients with HER2+ disease who had never received trastuzumab (6.1 months; hazard ratio (HR) for death 1.34, 95% confidence interval (CI) 0.78–2.30, P = 0.28) and patients with HER2– breast cancer (6.3 months, HR for death 1.66, 95% CI 1.31–2.12, P < 0.0001).24 This evidence concerns the gene ERBB2 and breast cancer.