In our co-culture experiments, mRNA and protein expressions of FASL in RA-treated Sertoli cells as well as FAS and Caspase 8 in lymphocytes were significantly suppressed, which indicates that Sertoli cell - lymphocyte FAS/FASL/Caspase8 system was disturbed by 9cRA. Here, FASLG is linked to rheumatoid arthritis.