Xa, or Tenascin XA (pseudogene), is a human gene encoded by TNXA. It may also be known as: Putative tenascin-XA; TN-XA; D6S103E; HXBL; TNX; XA. The encoded protein has an amino acid length of 311 and a mass of 33.7 kDa. Other isoforms may exist. Homologs of this gene exist in other organisms, including: Fly, Frog.