IGF1 and rotator cuff syndrome: Many growth factors such as bone morphogenetic proteins (BMPs), basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), insulin-like growth factor 1 (IGF-1), and transforming growth factor-b (TGF-b) have shown to be promising agents for rotator cuff tears in vivo and in vitro [5, 6].