The importance of integrin is further supported by increased expression in human myxomatous mitral valve tissues, the association of juvenile idiopathic arthritis and MVP with FBN1 mutations involving integrin binding sites (40), and the demonstration that mechanical stretching can stimulate Akt/mTOR signaling via β1 integrin, resulting in ECM production (41). Here, FBN1 is linked to juvenile idiopathic arthritis.