SIRT1 and intervertebral disk degenerative disorder: Of interest, Yurube et al. reported that β-actin expression was reduced during the development of disc degeneration [24] Therefore, β-actin expression may be susceptible to cellular stresses and the SIRT1 expression regulated by the β-actin promoter reduced even in SIRT-KI chondrocytes and mice, although detailed mechanism needs to be examined.