CCL2 and myalgic encephalomeyelitis/chronic fatigue syndrome: Based on these findings, we therefore hypothesized a pro-inflammatory pattern in CFS and FM patients with elevated pro-inflammatory immune markers (like IFN-γ, IL-1β, IL-6, IL-8, Interferon gamma-induced protein (IP)-10, TNF-α, and MCP-1); lower levels of anti-inflammatory (like IL-1ra and IL-10), and regulatory (like IL-4, TGF-β1, TGF-β2, TGF-β3, and IL-17) immune markers.