Elevation in pan caspase activity (the activity of multiple caspases, namely caspase 1, 3, 4, 5, 6, 7, 8 and 9) and depolarization of mitochondrial membrane potential (MMP) were also observed in 20 μM UA-treated breast cancer cells and again the effects were more pronounced in MDA-MB-231 cells (46.01% of cells with multicaspase activity, 41.93% of cells with depolarized MMP) and SK-BR-3 cells (54.38% of cells with multicaspase activity, 42.7% of cells with depolarized MMP) than in MCF-7 cells (13.17% of cells with multicaspase activity, 24.56% of cells with depolarized MMP) (Fig. 3). This evidence concerns the gene CASP1 and breast cancer.