Although the incidence of infections and serious infections (defined as life-threatening, requiring hospitalization or intravenous antibiotics) in the randomized controlled registration trials of the first 3 TNF inhibitors etanercept, infliximab and adalimumab mostly did not report significant increases in infection risk with these products in comparison with controls [9], epidemiological studies as well as registry data have revealed increased incidences of infection with these compounds (reviewed in [9]). Here, TNF is linked to infection.