AKR1C3 and breast cancer: Although AKR1C3 has been reported to be upregulated in pre-invasive and malignant breast cancer tissues compared to normal breast tissue (17, 18), and its expression shown to correlate with poor prognosis and an increased rate of late recurrence (18, 19), other studies have found variable or downregulated AKR1C3 expression in breast cancer tissues (20, 21).