Secreted abundant heat soluble (SAHS) proteins are similar to fatty acid-binding proteins, notably in their structure with an antiparallel beta-barrel and internal fatty acid binding pocket. SAHS proteins are often secreted into media and associated with special extracellular structures. Dried tardigrades have an abundance of secretory cells which are not found in hydrated individuals. The mechanism behind SAHS proteins has not yet been determined, but the presence of secretory cells only during desiccation suggests they are used to protect cells during periods of dehydration.