AT-101 employs the SAPK/JNK pathway to induce apoptosis. A: AT-101 (5 μM) induced SAPK/JNK in U937 and Jurkat T cells can be inhibited by the SP600125 kinase inhibitor; t = 90 min. B: Blockade of SAPK/JNK signaling by kinase inhibitor (SP600125) or dominant-negative c-Jun (TAM-67) inhibits AT-101 (5 μM)-induced apoptosis at t = 20 h in U937 cells. Data are presented as mean values (± SD) from 2 independent experiments. *p < 0.005, Student's t test.