MSH6 and rheumatoid arthritis: Oxidative stress can downregulate the DNA MMR system in RA-FLSs by inhibiting hMSH6. The oxidative stress environment can interfere with the repair process of single-base mutations and DNA damage by inhibiting hMSH6 (102, 103), and mutations in genes, such as P53 and LBH, can lead to pathological behaviors, such as invasion and proliferation of RA-FLSs (104, 105).