Autologous collagen-induced chondrogenesis (ACIC) is a representative single-stage surgical procedure that uses atelocollagen mixed with fibrin gel as a scaffold under arthroscopic CO2 gas insufflation.[18] Since the procedure is performed arthroscopically, fast recovery and good results can be expected.[19,20] Recently, a cell therapy product of transforming growth factor (TGF)-β1-expressing chondrocytes has been commercially available for the treatment of knee osteoarthritis. Here, TGFB1 is linked to osteoarthritis, knee.