Ex vivo killing of bone marrow cells from MDS patients by BAY11-7082 or bortezomib. Representative fluorescence-activated cell sorter (FACS) pictograms as obtained for CD34⁺ cells from patients 24 with low-risk MDS and 54 with high-risk MDS (A) (Table 1) 12 hours after culture in the presence or absence of BAY11-7082 or bortezomib. The numbers in each quadrant indicate the percentage of cells exhibiting the indicated changes. (B) Inverse correlation between p65 translocation and spontaneous apoptosis upon overnight in vitro culture of CD34⁺ cells from different MDS patients. Each point represents 1 patient. The correlation coefficient was determined by linear regression. (C) Statistical comparison of low- and high-risk patients treated and evaluated as in panel A. Note that BAY11-7082 or bortezomib only enhanced the rate of spontaneous apoptosis in high-risk but not in low-risk MDS.