Two opposite therapeutic redox-modulating strategies for the treatment of CLL. (A) Using antioxidant to neutralize ROS, CLL cells produce and release ROS into the microenvironment and ROS are dangerous to T cells. Antioxidant can neutralize ROS and prevent ROS-mediated damage to T cells. (B) Rapid induction of ROS. Blocking the mETC causes rapid ROS production by mitochondria and this could induce apoptotic cell death of CLL cells.