TNF and necrotizing vasculitis: Our report, as few cases in literature (Feinstein and Arroyo, 2005; Brik et al., 2007; Guillevin and Pagnoux, 2007; Braun-Moscovici et al., 2008; Eleftheriou et al., 2009; Valor et al., 2013; Zoshima et al., 2013), supports a role of anti-TNF therapy in rare systemic vasculitis and, indirectly, it gives evidence that increased levels of TNF-alpha may play a critical role in the inflammatory process associated with PAN.