In rheumatoid arthritis and Sjögren’s disease, blocking IL-1 with antibodies alleviated fatigue symptoms6,7, serum TNF-α and IL-6 levels increased in patients with depression22, and serum IL-1RA, IL-6, TNF-α, and IP-10 levels increased in patients with cancer and fatigue23,24. Here, IL6 is linked to rheumatoid arthritis.