TNF and rheumatoid arthritis: NF-kB is overexpressed in RA synovial tissue [24] and regulates the expression of genes such as TNF-α, IL-6, IL-8, various chemokines, vascular endothelial growth factor (VEGF), and matrix metalloproteinase (MMP) 1, 3, and 13, which are associated with inflammation, angiogenesis, and tissue destruction [25].