MPO and rheumatoid arthritis: Several studies by Bergt et al., Buss et al., Dalle-Donne et al., Davies et al., and Robaszkiewicz et al. [92,93,94,95,96] agree with our findings that 3-chlorotyrosine serves as a useful biomarker of protein damage by myeloperoxidase; it has been observed in a variety of pathological processes, such as atherosclerosis, glomerulonephritis, cystic fibrosis, rheumatoid arthritis, asthma, and Alzheimer’s disease.