Furthermore, genistein treatment of MDA-MB-231 BC cells resulted in G2/M cell cycle arrest as evidenced by a strong concentration-dependent reduction in the protein levels of cyclin B1, Cdk1, and Cdc25C; in particular, these results were mediated by a genistein-induced stable activation of ERK1/2 in a concentration- and time-dependent manner [199]. This evidence concerns the gene CCNB1 and breast cancer.