AEB071 antagonizes microenvironment stimuli and stromal-induced protection. CD19⁺ cells from CLL patients (N = 12-21) were incubated with 1 μM AEB071 and 1 μg/mL CD40L (A), 50 ng/mL BAFF (B), 20 ng/mL TNF-α (C), 800 U/mL IL-4 (D), and 100 ng/mL CXCL12 (E). Viability at 72 hours was determined by MTS. Dark lines represent averages. (F) CD19⁺ cells from CLL patients (N = 7) were isolated from peripheral blood and incubated with AEB071 (1 μM) in suspension or in coculture with 9-15c stromal cells for 48 hours. Viability was determined by annexin V/PI flow cytometry. Dark lines represent averages.