In humans, deregulated TGF-β signaling caused by the mutations of TGFΒR2, TGFΒ2, TGFΒ3, SMAD2, SMAD3, and FBN-1 is associated with Loeys-Dietz syndrome or Marfan syndrome, both of which are characterized by various skeletal anomalies such as long bone overgrowth72–77 (Table 2). The gene discussed is FBN1; the disease is Marfan syndrome.