In other tissues, the importance of MBs in maintaining tissue function is highlighted in Marfan syndrome, an autosomal dominant disease caused by defects in the FBN1 gene (Dietz et al., 1991), leading to a lack of/disorganised elastic tissue in the extracellular matrix, resulting in cardiovascular, skeletal, and ocular abnormalities. The gene discussed is FBN1; the disease is Marfan syndrome.