TSH, or Thyroid stimulating hormone, beta, is a human gene encoded by TSHB. It may also be known as: Thyrotropin subunit beta-B-beta; Thyrotropin beta chain; Thyrotropin alfa; Thyroid-stimulating hormone subunit beta. The encoded protein has an amino acid length of 138 and a mass of 15.6 kDa. Other isoforms may exist. TSH is a member of the Glycoprotein hormones subunit beta family. Homologs of this gene exist in other organisms, including: Fly, Frog.