LU’s ability to block progestin-induced VEGF production in human breast cancer cells could also be due to suppression of the phosphoinositide-3′-kinase pathway (Bagli et al. 2004), or inhibition of the SP-1 transcription factor, both of which are known to control progestin-induced VEGF induction in human breast cancer cells (Wu et al. 2004). Here, SP1 is linked to breast carcinoma.