ACAN and atrial fibrillation: Increased mRNA expression of ECM genes s SOX9, collagen type 2 (COL2A1), and aggrecan (ACAN) and downregulation of MMPs, ADAMPTS, and pro-inflammatory factors were observed in comparison to monocultures when paracrine interactions in a co-culture system were investigated after obtaining MSCs, AF, and NPCs from same donor [74].