Preliminary data demonstrated an ORR of 66% and 50% in the HER2+ and HER2low population, respectively, while median PFS was 11.6 months (95% CI 6.9–not reached) and 7.0 months (95% CI 2.3–10.8) for HER2+ and HER2-low BC patients, respectively. This evidence concerns the gene ERBB2 and breast cancer.