GZMB and rheumatoid arthritis: In addition, animal experiments have demonstrated that GZMB gene silencing can inhibit the mitogen-activated protein kinases (MAPK) signaling pathway by regulating the expression of inflammatory factors, apoptosis-related factors (BCL-2 and caspase) and angiogenesis-related factors [vascular endothelial-derived growth factor (VEGF) and basic fibroblast growth factor (bFGF)], thus alleviating synovial tissue hyperplasia and articular cartilage tissue damage caused by RA (15, 16).