CPPED1, also known as Serine/threonine-protein phosphatase 6 regulatory subunit 2, is a key regulatory protein involved in cellular signaling pathways. Primarily found in the cytoplasm and nucleus, CPPED1 functions as a regulatory subunit of protein phosphatase 6 (PP6), a member of the PPP family of serine/threonine phosphatases. It plays a crucial role in modulating PP6 activity, which is vital for processes such as cell cycle progression, DNA damage response, and protein degradation. Through its interaction with PP6, CPPED1 helps regulate substrate specificity and the enzyme’s subcellular localization.