Most recently, avacopan, an orally administered selective antagonist of the C5a receptor (C5aR) [3, 4], was approved by the US Food and Drug Administration in October 2021 as an adjunctive treatment for adult patients with severe, active ANCA-associated vasculitis in combination with standard therapy including glucocorticoids. The gene discussed is C5AR1; the disease is anti-neutrophil cytoplasmic antibody-associated vasculitis.