PCNA and pancreatic neoplasm: Although our treatment protocol failed to control the growth of established tumors, it does not necessarily imply that JNK inhibition is ineffective against bulk pancreatic tumors in vivo in any condition, since a recent report clearly demonstrated that the growth (assessed by tumor area) and the tumor cell proliferation (assessed by proliferating cell nuclear antigen positivity) of pancreatic tumors developing in K-RasG12D + Tgfbr2KO mice were significantly inhibited by systemic administration of JNK inhibitors [21].