IFNAR1 and systemic lupus erythematosus: Anifrolumab is a monoclonal antibody against the type I interferon receptor subunit 1 (IFNAR1), which has been shown to be effective in a phase 3 clinical trial in SLE patients who received 300 mg intravenous injection every 4 weeks for 48 weeks according to the British Isles Lupus Assessment Group (BILAG)-based Composite Lupus Assessment (BICLA) response (5).