As ROS can also activate SIRT3 expression15,29 and our findings that long-term exposure (4 h) of CLL cells to H2O2 may result in SIRT3 upregulation (Fig. 1F), we further analyzed the H2O2-exposed CLL cell lysates used above (P1–P5) to assess the expression status of SIRT3 and SOD2 in western blots. Here, SOD2 is linked to B-cell chronic lymphocytic leukemia.