BCL2 and cancer: Given that the simplified Bcl-2 network model (i.e., model II) accounts for the basic kinetic properties of mitotic death response, we next investigate whether it can be employed to examine the variable single-cell death responses in different cancer cell types during mitotic arrest, e.g., the four representative cell lines HeLa, U-2 OS, OVCAR-5 and A549 (Fig. 1A).