ABCB1 and cancer: Assuming that drug concentration is not impacted by the activity of MDR1, phases of the cell cycle are not forced by irregularly expressed cyclins, the SAC signal is not silenced without prerequisites being satisfied, and the APC/c is not prematurely activated, the taxane-treated cancer cell still needs to activate pro-apoptotic pathways and silence anti-apoptotic/pro-survival pathways.