MCL1 and B-cell chronic lymphocytic leukemia: Because MCL-1 is a ROS-sensitive anti-apoptotic protein that plays an important role in the survival of CLL cells [13] and is up-regulated in primary 17p- CLL cells and leukemic splenocytes from TCL1-Tg:p53−/− mice [10], we tested the possibility that PEITC might induce degradation of MCL-1 in 17p- CLL cells owing to its ability to induce severe ROS stress.