Insulin-like growth factor-I inhibits progesterone receptor expression in breast cancer cells via the phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin pathway: Progesterone receptor as a potential indicator of growth factor activity in breast cancer. - Cui,X.; Zhang,P.; Deng,W.; Oesterreich,S.; Lu,Y.; Mills,G.B.; Lee,A.V. (Mol Endocrinol, 2003)