BDKRB2 and rheumatoid arthritis: B2R have been found in synovial cells, fibroblasts, and chondrocytes in OA patients,134 while B1R has been found in rheumatoid arthritis synovial tissue and fibroblast-like synoviocytes (FLSs).135 Activated B2R can initiate signaling cascades that lead to painful and inflammatory responses and thus might potentially contribute to cartilage degradation in OA pathology.134 These findings suggest that B2R antagonists may be beneficial in treating OA.