NID2 and chordoma: The expression of many extracellular matrix proteins and cytoskeletal proteins, such as LAMA4, LAMB1, LAMB2, LAMBC1, NID1, NID2, NEXN, COTL1 and MYL9, changed significantly in endophytic chordomas, and TGFβ1,which was down-regulated, is the main protein upstream of these molecules.