Collaborative effects of IL24 and TNF-α on MLL/AF4-positive cell lines. (A) Apoptotic rate of MLL/AF4-positive ALL cell line with IL24 administration dependent on IL24 and TNF-α concentration. TUNEL assay showed that IL24 significantly increased TNF-α–induced apoptosis in MLL/AF4-positive ALL cell lines (SEM, IL24 0 ng/mL vs 1 ng/mL vs 10 ng/mL, P = .80 vs P = .016 vs P = .009; RS4;11, IL24 0 ng/mL vs 1 ng/mL vs 10 ng/mL, P = .72 vs P = .026 vs P = .070). (B) WB of lysate of MLL/AF4-positive cell lines under IL24 and TNF-α Western blotting analysis indicated that S100A6 up-regulation by TNF-α was inhibited and that p53 acetylation was activated in a manner dependent on the IL24 concentration in MLL/AF4-positive ALL cell lines. BiP, HOXA9, and MEIS1 in the presence of both IL24 and TNF-α did not change significantly from those in the presence of IL24 without TNF-α.