Low cytoplasmic CYP2S1 and nuclear CYP2W1 expression (Figure 6A) (p = 0.035), and high nuclear CYP2S1 and cytoplasmic CYP2W1 expression (p = 0.023) (Figure 6B), were significantly associated with adverse breast cancer specific survival in the total patient cohort. This evidence concerns the gene CYP2S1 and breast cancer.