GCA: giant cell arteritis, VZV: varicella-zoster virus, MI: myocardial infarction, EBV: Epstein-Barr virus, ESR: erythrocyte sedimentation rate; CRP: C-reactive protein, 18F-FDG-PET: 18F-fluorodeoxyglucose positron emission tomography, MRI: magnetic resonance imaging, IL-1: interleukin-1, IV: intravenous, TA: temporal artery, CTLA4-Ig: cytotoxic T-lymphocyte-associated protein 4 immunoglobulin, IL-6: interleukin-6, TCZ: tocilizumab. The gene discussed is CTLA4; the disease is arteritis.