The combined effect of Herceptin and FKA on downregulation of Cdc2 inhibitors (i.e., Myt1 and Wee1) and inhibitors of apoptosis (i.e., survivin and XIAP) is likely attributable to the enhanced growth inhibition of HER2-overexpressing breast cancer cells by these two agents. This evidence concerns the gene XIAP and breast carcinoma.