ESR1 and neoplasm: Assessment of the features variance among different annotated tumour areas within the same case revealed that the features variance within HER2‐positive/ER‐negative tumours was significantly less than that corresponding within HER2‐positive/ER‐positive regarding nuclear area median difference (2.1 vs. 7.5, p = 0.02), nuclear area SD median difference (1.02 vs. 4.3, p = 0.003) and nuclear area variance mean difference (68.3 vs. 122, p = 0.017) (Figure S3).