To further study the impact of leptin on the changes of FLSs under hypoxic conditions, three siRNAs targeting leptin (siLep-1, siLep-2, and siLep-3) were used to silence leptinexpression in RA-FLSs and siLep-2 was observed having the highest inhibitory efficacy (Figures 4(a) and 4(b)). This evidence concerns the gene LEP and rheumatoid arthritis.