Prognostic analysis using IHC staining on tissue microarrays from Ruijin cohort showed that MKP1 expression was associated with worse DFS and OS in 152 tamoxifen-treated but not in 251 aromatase inhibitors-treated ER + breast cancer patients (Fig. 3C-E, Fig. S4E, S4G). Here, ESR1 is linked to breast cancer.