In an animal model of fibromyalgia, etanercept demonstrated a substantial decrease in pain and decreased pain sensitization in thermal hyperalgesia and mechanical allodynia by lowering the production of pain-related inflammatory mediators, including c-FOS, nerve growth factor (NGF), TNF-α, IL-1β, IL-6, MCP-1, and GFAP. This evidence concerns the gene IL1B and fibromyalgia.