Rossi et al. studied the prognostic differences between HER2 0/1+/2+ tumours [47] in a cohort that included 15% of TNBC, and observed at diagnosis larger tumours, frequently more proliferative tumours (higher-grade, higher Ki-67 rate), and more extensive axillary lymph node involvement in patients with tumours with HER2 scores of 0 and 1+, compared to HER2 score 2, regardless of HR (hormone receptor) status. Here, MKI67 is linked to neoplasm.