The pro-apoptotic Bcl-2 family proteins Bax and Bak have been shown to be required for the disruption of mitochondrial and intrinsic death of cancer cells, where as the antiapoptotic Bcl-2 family proteins (Bcl-2 and Bcl-xl) can prevent cell death by interfering with the activation of Bax and Bak [22]. This evidence concerns the gene BCL2 and cancer.