TNF and rheumatoid arthritis: Differently from the population studied by Herbrig et al. [29], we enrolled long-standing RA patients with moderate-high disease activity (DAS28 ≥ 3.2) nonresponders to standard Disease Modifying Anti-Rheumatic Drugs (DMARDs) and eligible for anti-TNF therapy; in this population we detected a reduced number of circulating EPCs compared to healthy subjects not correlating with disease activity.