AKT1 and neoplasm: Additional studies determined that the synergistic inhibition of MCF-7 and MDA-MB-231 tumor cell growth resulting from combined low dose treatment of γ-tocotrienol with PPARγ antagonists was associated with a reduction in PPARγ, PPRE mediated reporter activity, and RXR, an increase in PPARγ coactivator expression, and a corresponding suppression in PI3K/Akt mitogenic-signaling.