CPPED1, also known as Serine/threonine-protein phosphatase 6 regulatory subunit 2, is an important regulatory protein involved in cellular signaling pathways. Located mainly in the cytoplasm and nucleus, CPPED1 acts as a regulatory subunit of protein phosphatase 6 (PP6), part of the PPP family of serine/threonine phosphatases. It plays a key role in modulating PP6 activity, which is essential 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.