- Estradiol induction of cAMP in breast cancer cells is mediated by foetal calf serum (FCS) and sex hormone-binding globulin (SHBG). Fortunati, N., Fissore, F., Fazzari, A., Piovano, F., Catalano, M.G., Becchis, M., Berta, L., Frairia, R. J. Steroid Biochem. Mol. Biol. (1999)