MPO and systemic lupus erythematosus: The most frequently occurring keyword was a neutrophil extracellular trap (1608), followed by inflammation (485), NETosis (321), extracellular trap (307), infection (261), DNA (261), myeloperoxidase (248), immunity (235), innate immunity (223), systemic lupus erythematosus (221), NADPH oxidase (195), elastase (174), cell death (172), apoptosis (171), and mitochondrial DNA (165).