PDYN also known as Prodynorphin is a preproprotein that is proteolytically processed to form the secreted opioid peptides beta-neoendorphin, dynorphin, leu-enkephalin, rimorphin, and leumorphin. PDYN plays a critical role in the production of bioactive peptides that interact with the κ-opioid receptor, which is essential for modulating pain and stress responses. Notably, PDYN undergoes post-translational modifications, including proteolytic cleavage, to yield several active peptides such as β-neoendorphin and dynorphin, which are involved in various physiological processes, including analgesia and mood regulation. Understanding the processing and function of PDYN is vital, as dysregulation of opioid peptides can lead to conditions such as chronic pain and addiction.