A recent post hoc analysis from the Adjuvant Lapatinib and/or Trastuzumab Treatment Optimisation (ALTTO) trial described the clinicopathological differences of HER2+ breast cancer patients relapsing within and after 12 months from the end of the adjuvant anti-HER2 therapy and showed that a treatment-free interval of <12 months has a strong negative prognostic impact, suggesting implications for the subsequent management of the metastatic setting.19 This evidence concerns the gene ERBB2 and breast cancer.