ESR1 and neoplasm: Compared to ER+PR+HER2− tumours of grade I, tumours of grade II or III were associated with increased mortality both early and late, with strongest associations for grade III (early: HR = 3.9 (95% CI 2.9–5.3), late: 2.9 (2.0–4.1), Fig. 1m, Additional File 9).