In cases where systemic vasculitis is diagnosed, gastrointestinal vasculitis must be taken into account in patients presenting with signs of gastrointestinal ischemia and elevated inflammation markers such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), especially in the absence of other risk factors for atherosclerotic vascular disease. The gene discussed is CRP; the disease is necrotizing vasculitis.