The effect of stroma-based conditions vs MCM on AML cell response to BCL2 inhibitors. (A-B) Samples show decreased sensitivity to BCL2-specific inhibitor venetoclax and to BCL2/BCLXL inhibitor navitoclax in the presence of HS-5 CM. (C-E) CM results in decreased BCL2 expression and induction of BCLXL and BCLXS expression in AML patient cells. (F) No difference in MCL1 expression was detected in the 2 conditions. Bar plots represent the mRNA expression for BCL2 genes after 48 hours of incubation of AML cells (n = 6) in 25% HS-5 CM and MCM medium. Data are normalized against GAPDH expression and error bars represent standard deviation of at least 2 replicates. (G) Flow cytometry analysis showing an amount of live CD45⁺ AML cells cultured in RPMI, 25% HS-5 CM, or RPMI supplemented with 10 ng/mL GM-CSF or G-CSF after 48 hours of treatment with venetoclax (100 nM). Error bars represent standard deviation of 3 replicates. ns, not significant. *P < .05; **P < .01; ***P < .001; ****P < .0001.