Altogether, our pilot study suggests that: (i) at least in the Luminal subclass, the ZNF217-WT-ΔE4 gene expression signature has a better prognostic value than that of ZNF217-WT mRNA levels alone, ZNF217-ΔE4 mRNA levels alone or that of the other conventional prognostic parameters of breast cancer; and (ii) in the Luminal subclass, the prognostic value of the ZNF217-WT-ΔE4 gene expression signature recapitulates that of ZNF217-E3 mRNA levels. Here, ZNF217 is linked to breast cancer.