1. MitoROS increased in blood and monocytes (20)2. GSH and GPx decreased in blood (40)3. MDA increased in blood, RBC and synovial fluid; TBARS increased in blood; F2-I increased in plasma; MAA adducts increased in synovium (20, 39);4. MDA increased, GPX4, SLC7A11 and SLC3A2L decreased in LPS-treated synoviocytes (38)5. 4-HNE increased in the hyperplastic synovium of RA patients compared with OA patients (39). This evidence concerns the gene GPX4 and rheumatoid arthritis.