The frequency of mRNA over-expression (z score > 2) in the different sub-groups of luminal breast cancers classified according to the 3-gene classifier for EIF4EBP1 and LSM1 was higher for the ER+/HER2-/proliferation high group compared with the ER+/HER2-/proliferation low group, suggesting that, in both gene cases, increased gene dosage in luminal B cancers translates in higher mRNA production and possibly increased protein that could lead to inferior RFS outcomes (Figure 10). This evidence concerns the gene ERBB2 and breast cancer.