The presence of high titers of P-ANCA and anti-MPO with multiantigenicity, the positive anti-histone antibodies, and the lack of immunoglobulin and complement deposition histopathologically are features that have been described with drug-induced ANCA vasculitis [3, 4] rather than with drug-induced lupus or with primary vasculitis. The gene discussed is MPO; the disease is vasculitis.