As for the interactive effects of CS with gene polymorphisms on RA epigenome, Meng et al. identified a significant interaction between rs6933349 of mucin 22 (MUC22) and CS in DNA methylation of cg21325723 in terms of the risk of developing ACPA-positive RA in both Caucasian and Asian populations [138]. Here, MUC22 is linked to rheumatoid arthritis.