IFI6 and breast cancer: Identification of G1P3 as a poor prognostic factor in breast cancer challenged the dogma that upregulated ISGs in cancer cells are beneficial.3 Conforming to its localisation in mitochondria, G1P3 antagonised intrinsic apoptosis in a variety of cancer cells.2, 4 Antiapoptotic function of G1P3 could in part explain the association between G1P3 upregulation and poor RFS,3 but not poor DMFS identified in the current study (Fig. 1a and supplemental Figures. 1A and 1B).