Conversely, while Ppif−/− mice also developed M/D-driven mammary tumors with complete penetrance (data not shown), these lesions expressed limited ER levels (Fig. 1B) and emerged with significantly accelerated kinetic as compared to their WT counterparts (median TFS: 69 days; p value: 0.0213) (Fig. 1C). This evidence concerns the gene PPIF and breast cancer.