A remarkable observation in this context is that TNFR1-mediated activation of JNK, as well as of the oncogenic transcription factor STAT3 and associated IL-6 production promote obesity-related hepatocarcinogenesis, which is also strongly reduced in TNFR1-deficient mice22. The gene discussed is MAPK8; the disease is obesity due to melanocortin 4 receptor deficiency.