The cover figure depicts proposed mechanisms of action of the promising natural preventive agent deguelin. Previous work has demonstrated that deguelin inhibits the phosphatidylinositol 3-kinase (PI3K)/AKT and nuclear factor kappa B (NF-κB) signaling pathways in regulating gene expression (left side). Now, novel findings reported in this issue of the journal demonstrate that deguelin also regulates the wnt/β-catenin pathway (right side) in ER-negative breast cancer cells. Deguelin inhibited both ER-positive and -negative breast-cancer cell growth, but most strongly in ER-negative cells, causing a cell-cycle blockade and inducing apoptosis. Deguelin joins only a small group of agents shown to inhibit the growth of ER-negative breast cancer cell lines. See articles by Murillo et al. (beginning on page 942) and Rodenberg and Brown (beginning on page 915) for more information.

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