In BC cells, multiple factors, including growth factor, DNA damage, reactive oxygen species (ROS), and UV radiation, can promote uncontrolled cell growth through mitochondrial, FasL/Fas–, PI3K/AKT–, ROS-, nuclear factor κB (NF-κB)–, and MAPK–mediated pathways, to break the balance of proapoptotic and antiapoptotic effects. This evidence concerns the gene FAS and breast cancer.