Thymosin alpha 1 (Tα1) is a naturally occurring peptide produced in the thymus gland and is known for its immunomodulatory properties.

 It's a small protein of 28 amino acids that helps enhance the immune response by stimulating T cells, which are crucial for adaptive immunity. Tα1 has been used in various clinical applications, including treating immunocompromised states, infections, and cancers.