On the Cover: Combined exposure of MCF7 breast cancer cells to low doses of rosiglitazone and 9-cis-retinoic acid disrupts mitochondrial membrane potential and leads to apoptosis. Within these apoptotic cells, the dye JC-1 (5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolylcarbocyanine iodide) remains in the cytoplasm, which stains green (foreground), whereas in control cells, aggregation of JC-1 within mitochondria results in orange-red fluorescence (background). (See abstract NC 01 on page S8.)