CUL3 also known as Cullin3 is a member of the cullin protein family. CUL3 plays a crucial role in the ubiquitin-proteasome system, specifically in the selective degradation of proteins, which is vital for maintaining cellular homeostasis and regulating various biological processes, including cell cycle progression and signal transduction. CUL3 forms a part of the E3 ubiquitin ligase complex, where CUL3 associates with Nedd-8, enhancing activity and facilitating the ubiquitination of target substrates. CUL3′s ability to regulate protein degradation underscores its importance in cellular functions, as dysregulation can lead to various diseases, including cancer.