Treatment of CD5+CD19+ CLL B cells with PAPTP triggers an increase of mitochondrial reactive oxygen species (ROS) release (Fig. 1b) as well as depolarization of the mitochondrial membrane potential and cytochrome c release (Fig. 1b), in agreement with the general mechanism of action of PAPTP mentioned above [29]. The gene discussed is CD5; the disease is B-cell chronic lymphocytic leukemia.