Maisonneuve et al. [12] recommended the use of Ki-67 <14% and ≥20% levels to define luminal A and B tumours, respectively, and classified tumours with intermediate (14–19%) Ki-67 levels to a further extent according to low PgR (< 20%) or high PgR (≥ 20%) status. This evidence concerns the gene MKI67 and neoplasm.