Results indicated that the addition of PEGDA contributed to significantly better mechanical properties of the final PEGDA/DAFM/TGF-β1 hydrogels, and the released TGF-β1 facilitated the migration of AF cells, preventing NP atrophy, retaining disc height, and restoring the disc biomechanics (Fig. 6d). The gene discussed is TGFB1; the disease is atrial fibrillation.