TNF and myalgic encephalomeyelitis/chronic fatigue syndrome: The major eligibility criteria included: age ≥70 years; a Clinical Frailty Scale (CFS) (33) score of 5 or 6; a 6MWT distance of 200 to 400 meters; and concentration of serum tumor necrosis factor-alpha (TNF-α) equal to or higher than 2.5 pg/mL as a measure of inflammaging.