ERBB2 and neoplasm: Another line of evidence for breast tumoursbeing distinct entities was the increased formation of basaltype BCs in individuals positive for BRCA1. In terms ofclinical outcome, the basal and ERBB2+ subtypes arethe most severe in terms of the period of time betweenprimary tumour formation and metastasis, while theluminal B subtype is an intermediate between the two (9).