Defective apoptosis of CMML peripheral blood monocytes. (A) Cell viability of CD14⁺ monocytes sorted from the peripheral blood of patients with CMML (n = 16) and healthy donors (n = 27) was analyzed by Trypan blue dye exclusion after 4 days in culture without serum. (B) CD14⁺ monocytes were sorted from the peripheral blood of patients with CMML (n = 21) and healthy donors (n = 30) and stained with AnV-FITC and PI after 4 days in culture without serum; the AnV⁺/PI^– fraction was measured by flow cytometry. (C) AnV⁺/PI^– fraction of CD14⁺ monocytes sorted from the peripheral blood of patients with CMML (n = 78) and healthy donors (n = 102) as determined by flow cytometry after 24 hours in culture in the presence of 10% fetal calf serum. (D-E) Patient samples tested in panel C were classified according to patient characteristics, including the 2016 iteration of the World Health Organization classification separating CMML-0 from CMML-1 and CMML-2 (D) and the presence or absence of mutations in the indicated genes (E). Error bars are mean ± standard error of the mean (SEM). Mann-Whitney U test: *P < .05; ***P < .001; ****P < .0001. MUT, mutant; WT, wild-type.