ESR1 and cancer: In the internal validation cohort, survival prediction identified high-risk patients across different molecular subtypes, as demonstrated by a hazard ratio (HR) of 3·29 (0·91–11·94) (HER2+), 3·54 (1·52–8·20) (triple-negative), and 2·78 (1·45–5·31) (ER/PR+&HER2−), albeit results were not significant for HER2+ cancers.