ACR: American College of Rheumatology; EULAR: European Alliance of Associations for Rheumatology; GCA: giant cell arteritis; TAB: temporal artery biopsy; CDUS: colour Doppler ultrasound; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; FDG-PET: fluorodeoxyglucose-positron emission tomography. The gene discussed is CRP; the disease is arteritis.