Although originally named stress-activated protein kinases (SAPKs) for their profound response to extracellular stress stimuli such as UV-irradiation, heat shock, osmotic stress, reactive oxygen species and inflammatory cytokines, it is now apparent that JNKs are also activated by intracellular stimuli and biomechanical cues, and that persistent JNK activation underlies pathogenesis in a number of disease contexts, including cancer [2,3]. This evidence concerns the gene MAPK8 and cancer.