Comparing the effects of atranorin on normal mammary epithelial NMuMG cells and 4T1 cancer cells, it was observed that 4T1 cells were more sensitive to atranorin, reducing the clonogenic ability of carcinoma (75 μM), inducing apoptosis mediated by caspase-3 activation and poly ADP ribose polymerase (PARP) cleavage, and enhancing the depletion of Bcl-xL protein [57]. This evidence concerns the gene CASP3 and cancer.