FGF2 and atrial fibrillation: Growth factors used in AF tissue engineering have included basic fibroblast growth factor (bFGF), transforming growth factor (TGF)-β1, TGF-β3, and insulin-like growth factor (IGF)-1.21–24 Specifically, bFGF has not only been shown to stimulate fibroblastic differentiation of mesenchymal stem cells (MSCs) but also MSC proliferation and self-renewal.25 However, like most growth factors, bFGF has a very short plasma half-life (usually 90 s),26 thereby requiring repeated local administration for optimal effect.