Therefore, studies were conducted to characterize the role of PPARγ in mediating the effects of combined treatment of γ-tocotrienol with PPARγ agonists (rosiglitazone and troglitazone) or antagonists (GW9662 and T007907) on the growth of PPARγ negative +SA mouse mammary epithelial cells and PPARγ-positive and PPARγ-silenced (siRNA transfected) MCF-7 and MDA-MB-231 human breast cancer cells. This evidence concerns the gene PPARG and breast carcinoma.