Fibulins are a family of ECM glycoproteins characterized by a fibulin-type C-terminal domain preceded by tandem calcium-binding epidermal growth factor (EGF)-like modules. They are involved in protein-protein interaction with the components of basement membrane and extracellular matrix proteins. There are five fibulins, which can be classified into two subgroups. Fibulin-1 and -2 constitute one subgroup. These fibulins are larger than the others due to the presence of a higher number of EGF modules and an extra domain with three anaphylatoxin modules []. Members of the second subgroup, fibulin-3, -4, and -5, are similarly small in size and highly homologous to one another in modular structure. They consist of a modified cbEGF domain at the N terminus followed by five tandem cbEGF modules and the fibulin-type C-terminal region.This entry represents EGF-containing fibulin-like extracellular matrix protein 2 (Efemp2), also known as fibulin-4. Efemp2 binds to tropoelastin and may play an important role in the assembly of elastic fibres during development []. Defects in Efemp2 cause autosomal recessive cutis laxa, an heterogeneous group of connective tissue disorders characterised by cutaneous abnormalities and variable systemic manifestations such as loose skin. In addition to skin, internal organs enriched in elastic fibres, such as the lung and the arteries, are alsoaffected [, , ].
