As already described [48], BMP signalling reduces the expression of pro-inflammatory and pro-destructive factors in both unstimulated and stimulated RA synoviocytes, mainly with the IL-17A and TNF-α combination, so BMP signalling could have an anti-inflammatory role in the control and maintenance of low levels of pro-inflammatory factors in healthy synoviocytes and probably also in the early stages of RA. This evidence concerns the gene IL17A and rheumatoid arthritis.