Cellular senescence is an alternative fate of NPCs and is characterized by stable cell cycle arrest and the upregulation of related markers such as cyclin-dependent kinase inhibitor 2 A (CDKN2A/p16) and senescence-associated β-galactosidase (SA-β-gal), which play an important role in the process of disc degeneration [4–6]. This evidence concerns the gene CDKN2A and intervertebral disk degenerative disorder.