FGF2 and atrial fibrillation: With the same background and aim, TGF-β3 and bFGF were inserted into the decellularized NP matrix/chitosan (DNPM/chitosan) and decellularized AF matrix/chitosan (DAFM/chitosan) hydrogels respectively, revealing that the ornamental TGF-β3 and bFGF induced the secretion of COL I and COL II from NP stem cells and AF stem cells (AFSC) [58,60].