TRPS1 and intervertebral disk degenerative disorder: In a second phase, between day 7 and day 14, IVD cells combined with DWJM showed a down-regulation of SOX2 and SOX9 together with an up-regulation of TRPS1, a chondrogenic transcription factor previously identified by us as chondroprotective and associated with the lower grade of disc degeneration (Penolazzi et al., 2019).