IL6 and neurodegenerative disease: However, uncontrolled activation of microglia leads to the excessive release of various cytokines, such as tumor necrosis factor-alpha (TNF-α), prostaglandin E2 (PGE2), interleukin-6 (IL-6), nitric oxide (NO), and reactive oxygen species (ROS), which have been implicated in various neurodegenerative diseases.