Hch1, or AHA1, activator of heat shock 90kDa protein ATPase homolog 2 (yeast), is a human gene encoded by AHSA2. It may also be known as: Activator of 90 kDa heat shock protein ATPase homolog 2. The encoded protein has an amino acid length of 299 and a mass of 33.8 kDa. Other isoforms may exist. Hch1 is a member of the AHA1 family. Homologs of this gene exist in other organisms, including: Mouse, Rat, Chicken.