TGFB1 and synovitis: In turn, approaching the discussion of another crucial marker, TGF-β1, which is a complex cytokine, and considering its possible multifunctionality—reflected by multiple, and sometimes diverse, biological effects on fibroblast proliferation, extracellular matrix deposition, tissue remodeling and degradation, and pleiotropic cytokine action with both suppressive and inflammatory immune responses [71,72,73]—we found a correlation between ELISA-confirmed urinary TGF-β1 levels and the synovitis score in this study.