The level p16INK4a-positive cells were 8.9% higher in NP and 8.8% higher in AF cells from degenerate IVDs (p < 0.05) (Figure 2A,C), and the number of SA-β-gal-positive cells was 11.6% higher in NP and 8.8% higher in AF cells from degenerate IVDs, compared to the corresponding non-mild-degenerated discs from the same individual (p < 0.05) (Figure 2B,C). Here, CDKN2A is linked to atrial fibrillation.