Previously, Chen and coworkers [45] reported that BSO enhanced the apoptotic effect of arsenic (As2O3) in leukemia and lymphoma cells through activation of JNK and upregulation of death receptor (DR)5 and that inhibition of JNK by SP600125 decreased DR5 upregulation and apoptotic induction in U937 leukemia cells treated with arsenic plus BSO. The gene discussed is MAPK8; the disease is leukemia.