After exclusion of tumours with missing HER2 and/or PR status as well as ER−/PR+ tumours (considered an inconclusive subgroup [26, 27]), the tumours were classified as follows: ER+/HER2−, 61% (n = 255/415); HER2+, 16% (n = 65/415); and TNBC, 23% (n = 95/415) (Fig. 1). The gene discussed is ERBB2; the disease is neoplasm.