In a study on rheumatoid arthritis (RA), Sen et al. showed that WNT5A could induce the expression of the pro-inflammatory cytokine IL-6 in fibroblast-like synoviocytes (FLS) and the inhibition of WNT5A either with antisense or a dominant negative vector, reducing IL-6 levels in FLS obtained from patients with RA [24]. This evidence concerns the gene WNT5A and rheumatoid arthritis.