In the present study, we found that NFATC1 expression was higher in synovial tissues of RA patients than in those of OA patients, and that pretreatment of synovial cells with AT1R, ERK1/2, and JNK inhibitors, as well as siRNA-RANKL transfection mitigated Ang II-induced NFATC1 upregulation. This evidence concerns the gene MAPK8 and rheumatoid arthritis.