title: Decreased levels of complement components C4 and C2 in lupus erythematosus: genetic defect or complement activation?
mesh_terms: D003167:Complement Activation; D003175:Complement C2 / Q000032:analysis; D003181:Complement C4 / Q000032:analysis; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000235:genetics / Q000276:immunology*
chemical_list: D003175:Complement C2; D003181:Complement C4