“…Attracting factors include BMPs (Frenkel et al, 1996), hepatocyte growth factor (HGF) (Takebayashi et al, 1995), IGF-1 (Chang et al, 2003), TGF-ÎČ (Chang et al, 2003), PDGF (Fujita et al, 2004), FGF (Hidaka et al, 2006), fibronectin, fibrin and collagen type I (Maniwa et al, 2001). However, results remain contradictory for some of these factors, as testing of human chondrocytes revealed no effects for BMP-2, BMP-4, BMP-7, IGF and TGF-ÎČ in other studies (Mishima &, Lotz, 2008), being IGF-1, PDGF (Fiedler et al, 2004;Ozaki et al, 2007;Ponte et al, 2007) and VEGF the ones that induced higher response (Mishima & Lotz, 2008). Effects of GFs vary in vitro and in vivo, regarding animal species and specimens' age, among other aspects.…”