MARCHF2 (membrane associated ring-CH-type finger 2) is an E3 ubiquitin ligase that functions as a key regulator of antiviral immunity and protein degradation. The protein demonstrates broad antiviral activity by targeting viral envelope glycoproteins for degradation through the lysosomal pathway 1. MARCHF2 restricts HIV-1 viral production by inhibiting envelope protein translocation to the cell surface, thereby reducing viral cell-cell transmission 1. Additionally, MARCHF1, 2, and 8 block Ebola virus envelope glycoprotein cleavage by targeting the furin P domain, preventing viral maturation 2. The protein's tumor suppressor function is evidenced by its role as a novel SNAIL E3 ligase in triple-negative breast cancer, where MARCHF2 promotes SNAIL ubiquitination and degradation, thereby suppressing epithelial-mesenchymal transition and metastasis 3. Higher MARCHF2 expression levels are associated with better prognosis in breast and other cancers 3. The protein has also been identified as a prognostic biomarker in cervical squamous cell carcinoma 4 and shows genetic association with postprandial proinsulin levels 5, suggesting broader physiological roles beyond antiviral immunity.