Si-ZFAS1#1, si-ZFAS1#1 plus ADAMTS9, or pcDNA-ADAMTS9 was transfected into FLS-RA, and the inhibiting effect of ZFAS1 repression on the mRNA and protein levels of ADAMTS9 was rescued by ADAMTS9 up-regulation in vitro, while ADAMTS9 expression level was increased due to the introduction of pcDNA-ADAMTS9 (Figure 4A,B). This evidence concerns the gene ZFAS1 and rheumatoid arthritis.