Tenascin X

A member of the tenascin family, tenascin X (TN-X) also known as hexabrachion-like protein is a glycoprotein that is expressed in connective tissues including skin, joints and muscles. In humans, tenascin X is encoded by the "TNXB" gene.
Gene.
This gene localizes to the major histocompatibility complex (MHC class III) region on chromosome 6. The structure of this gene is unusual in that it overlaps the CREBL1 and CYP21A2 genes at its 5' and 3' ends, respectively.
Function.
This gene encodes a member of the tenascin family of extracellular matrix glycoproteins. The tenascins have anti-adhesive effects, as opposed to fibronectin which is adhesive. This protein is thought to function in matrix maturation during wound healing.
Clinical significance.
Deficiency causes Classical-like Ehlers–Danlos syndrome, where collagen density is reduced and elastic fibers are fragmentated.