Another phase II trial is ongoing to study how green tea extract works in preventing breast cancer compared to a placebo in 1084 cases of postmenopausal women by evaluating its effects on breast cancer biomarkers, including mammographic density, plasma insulin-like growth factor 1, IGF binding protein 3, and estrone (ClinicalTrials.gov Identifier: NCT00917735). Here, IGF1 is linked to breast cancer.