Based on the concordant associations between CYP27A1 protein and mRNA expression and premenopausal ER+ BC prognosis observed in this study, the contradictory results reported in the former IHC-based study16 may be likely attributed to the more generous use of systemic adjuvant therapies like chemotherapies and/or ovarian suppression treatments. The gene discussed is CYP27A1; the disease is breast cancer.