CYP24A1 and prostate cancer: A randomized controlled intervention study in patients diagnosed with adenomatous polyps showed no reduction in cell proliferation of the colorectal epithelium after a 12‐month dietary soy isoflavone intervention.35 Furthermore, in a patient‐derived prostate cancer xenograft model administration of genistein at low (80 mg/kg/day) as well as high (400 mg/kg/day) doses resulted in more metastases and in increased cell proliferation and decreased apoptosis in these metastases but not in primary tumours.36 This suggests that the activity of genistein is wider than just inhibition of CYP24A1.