IL6 and nervous system cancer: The HES1 is a downstream target of the Notch signaling pathway, playing a promoting role in the differentiation and proliferation of neural stem cells.44 Elevated levels of IL-6 is present in the nervous system and can trigger cellular responses, mediate inflammation, play a role in neurogenesis, contribute to the development of neural tumors, influence cell growth and survival, and co-localize with neurotrophic factors.