TGFBR2 and intervertebral disk degenerative disorder: Three weeks after induction of disc degeneration, a total of 106 WJ-MSCs were transplanted into each degenerated disc and the radiologic and histologic characteristics were analyzed and compared 12 weeks after implantation according to the expression levels of TβRI/ALK5 and TβRII in the transplanted WJ-MSCs and the combined use of a XHA scaffold.