SMURF2 (SMAD specific E3 ubiquitin protein ligase 2) is an E3 ubiquitin ligase that regulates protein stability through targeted ubiquitination and proteasomal degradation. The primary function involves adding K6, K33, and K48 ubiquitin chains to target proteins, leading to their polyubiquitination and degradation 1. SMURF2 operates through direct protein interactions and can translocate from cytoplasm to nucleus to regulate signaling pathways 2. The enzyme targets multiple substrates including RACK1 in ovarian cancer 1, RUNX2 in calcific aortic valve disease through FOXO1-mediated regulation 3, GLI1 in Hedgehog signaling 4, PARP1 in DNA damage response 5, and PDE4B in neuroinflammation 6. SMURF2 exhibits tumor suppressive properties in several contexts, as its loss enhances cancer progression through substrate stabilization 14. Disease relevance includes roles in cardiac fibrosis where SMURF2 nuclear translocation inhibits SMAD2/3 signaling 2, hepatic fibrosis regulation 7, and Alzheimer's disease where it modulates microglial neuroinflammation 6. Clinically, SMURF2 expression levels correlate with patient prognosis and represent potential therapeutic targets across multiple pathological conditions 13.