TGFB1 and rheumatoid arthritis: B-cells are responsible for producing osteoclasogenic cytokines such as IL-6 (Mihara et al., 2011) and RANKL (Yeo et al., 2011) in RA progression, although they differentiate into regulatory B-cells that produce IL-10 and TGF-β to suppress osteoclasts (McInnes et al., 2016).