MAPK8 and cancer: JNK was persistently activated during incubation of ES cells with edelfosine, and JNK inhibition prevented edelfosine-induced apoptosis, suggesting a major role for JNK in the proapoptotic action of edelfosine on ES cells, in a similar way as previously found for the proapoptotic action of edelfosine in leukemic [38] and pancreatic [35] cancer cells.