DPM2 (dolichyl-phosphate mannosyltransferase subunit 2) is a regulatory subunit of the dolichol-phosphate mannose (DPM) synthase complex located in the endoplasmic reticulum 1. As a regulatory protein, DPM2 is essential for the stable expression and correct subcellular localization of the catalytic DPM1 subunit, with DPM2 stabilizing DPM3, which in turn stabilizes DPM1 2. DPM2 also enhances binding of dolichol phosphate substrate and increases DPM synthase activity approximately 10-fold 1. Beyond its canonical role in dolichol phosphate-mannose biosynthesis, DPM2 participates in the glycosylphosphatidylinositol-N-acetylglucosaminyltransferase (GPI-GnT) complex, contributing to GPI anchor biosynthesis 3. Pathologically, mutations in DPM2 cause congenital disorder of glycosylation 1U, a genetic disease affecting protein glycosylation. Additionally, a DPM2 genetic locus (DPM2-FAM102A rs3739821) shows significant association with primary angle closure glaucoma susceptibility 4. Recent evidence suggests DPM2 may function as an oncogene in breast cancer, with high expression correlating with poor prognosis and its transcriptional activation by estrogen receptor 1 5.