TGF-β1 has been speculated to stimulate chondrogenesis and the growth of articular chondrocytes.[28] It has significant roles in tissue regeneration, cell differentiation, and extracellular matrix protein synthesis.[29] Preclinical studies and placebo-controlled trials in patients with arthritis of the knee showed promising results of TGF-β1-transduced chondrocytes.[15]. This evidence concerns the gene TGFB1 and arthritic joint disease.