There has been prior evidence of PAN as an immune complex-mediated disease based on the high prevalence of IgM antiphosphatidylserine–prothrombin complex and immunoglobulin M and C3 deposits in vasculitis tissues.[14,15] Under this immune complex-mediated hypothesis, no virus will be detected in the vasculitis tissue. The gene discussed is F2; the disease is polyarteritis nodosa.