In 2021, a systematic review encompassing data from 13,557 patients across 159 articles concluded that the most promising synovial fluid biomarkers for knee osteoarthritis were inflammatory markers such as interleukins (IL-6, IL-8), tumor necrosis factor-α (TNF-α), as well as leptin, matrix metalloproteinases (MMP-1 and MMP-3), tissue inhibitors of metalloproteinases (TIMP-1), and vascular endothelial growth factor (VEGF) [36]. Here, TNF is linked to osteoarthritis, knee.