The results of our previous study also indicated that inhibitors of several receptor tyrosine kinases [see also, for example, reference [38], LY294,002 (inhibitor of PI3K), triciribine (inhibitor of Akt/PKB), and rapamycin (inhibitor of mTOR) up-regulated the p27-luciferase reporter activity in estrogen receptor (ER) -negative MDA-MB-231 human breast cancer cells in vitro [10]. Here, CDKN1B is linked to breast carcinoma.