Advanced genomic sequencing and pathways studies showed that only 65% of clinically defined HER2‐positive tumours are classified as HER2‐enriched (HER2‐E) using intrinsic molecular sub‐types classification [3, 4, 5], suggesting clinical, pathological and molecular heterogeneity related to HER2 expression level. The gene discussed is ERBB2; the disease is neoplasm.