Matrilin family consists of four non-collagenous extracellular matrix (ECM) proteins []. Matrilin-1 and matrilin-3 are expressed mainly in cartilage, while matrilin-2 and matrilin-4 are widely distributed in many connective tissues []. Typical matrilin has the similar domain structure with two von Willebrand factor A-like (VWA) domains interconnected by a variable number of epidermal growth factor-like (EGF) domains. The subunits form trimers or tetramers via a C-terminal α-helical coiled-coil domain [].Matrilin-2 (MATN2) is the largest and most complex matrilin. It is made up by two vWFA-like domains connected by ten EGF modules, and has a unique domain located between the second vWFA-like domain and the coiled-coil C-terminal domain []. MATN2 is a structural component of the ECM in many tissues, including the skin [, ]. It participates in peripheral nerve regeneration []and induces proinflammatory responses that could contribute to axonal damage in CNS inflammatory diseases []. It functions as a tumor suppressor in hepatocarcinogenesis [].
