MAN2C1 encodes a cytosolic alpha-mannosidase that cleaves α1,2-, α1,3-, and α1,6-linked mannose residues from free oligosaccharides (fOSs) generated during N-glycoprotein degradation pathways 1. This enzyme plays a critical role in fOS catabolism, with deficiency leading to accumulation and delayed processing of these substrates 1. Pathogenic variants in MAN2C1 cause congenital disorder of deglycosylation 2 (CDDG2), characterized by neurodevelopmental abnormalities including dysmorphic facial features, intellectual disability, and brain malformations such as polymicrogyria, interhemispheric cysts, and cerebellar hypoplasia 12. Beyond its metabolic function, MAN2C1 appears to have broader cellular roles. In cancer contexts, the protein can attenuate PTEN function by direct binding, thereby promoting AKT activation and tumor growth in prostate cancer 3. Additionally, MAN2C1 influences cell adhesion through modulation of CD54-LFA-1 interactions in T cells 4 and affects microtubule organization, with suppression causing mitotic arrest and apoptosis in cancer cells 5. The gene has also been implicated in late-onset Parkinson's disease susceptibility and PTSD-associated epigenetic modifications 67.