clomid and nolvadex pct 35 37, 46 In addition, despite the fact that both decorin and biglycan are capable of binding all three isoforms of TGF ОІ, analysis of bone cell extracts revealed that TGF ОІ is mainly bound to decorin s core protein and that the interaction between TGF ОІ and decorin actually increases the affinity of TGF ОІ to its receptors and, as a consequence, its activity