Based on our data we propose a two-step model on how JNK signaling regulates tumor growth: in an early wave of pathway activity, AP-1 induces the expression of targets such as cell death genes, puc, and Ets21C. In a wild-type background this leads to apoptosis as demonstrated by numerous studies16, 17, 18, 19. This evidence concerns the gene MAPK8 and neoplasm.