MPO and rheumatoid arthritis: At present, NETs are defined as web-like structures composed of DNA-histone complexes and cytoplasmic and granular proteins such as calprotectin, myeloperoxidase (MPO), and NE that, in addition to being involved in the defense against pathogens, may play a role in noninfectious pathologies such as obesity [31] and diabetes mellitus type II [32], atherosclerosis, thrombosis [33], psoriasis [34], systemic lupus erythematosus [35], rheumatoid arthritis [36,37], and cancer [38,39,40,41], among others.