Data from the POETIC trial showed that while high baseline Ki67 levels in ER+/HER2− tumours that dropped post POAI correlated with lower risk of recurrence measured by Ki67 categories, this was not seen in the ER+/HER2+ group, maybe because the anti-HER2 therapy they received compensated for or overcame the ET resistance. This evidence concerns the gene ESR1 and neoplasm.