MGAT2 (alpha-1,6-mannosyl-glycoprotein 2-beta-N-acetylglucosaminyltransferase) is a Golgi-localized glycosyltransferase that catalyzes the transfer of N-acetylglucosamine onto α-1,6-mannose residues in nascent N-linked glycan chains, creating the second branch in complex N-glycans 1. This enzyme is essential for converting oligomannose to complex glycan structures 2. The gene is located on chromosome 14 as a single-exon gene with housekeeping gene characteristics 12. MGAT2 shows particularly high expression in the small intestine and liver, where it regulates triglyceride absorption and homeostasis 34. Loss of MGAT2 function causes congenital disorder of glycosylation type IIa (CDG-IIa), manifesting as severe gastrointestinal abnormalities, hematologic defects, developmental disability, and immune dysfunction including hypogammaglobulinemia and defective lymphocyte proliferation 56. Therapeutically, MGAT2 inhibition shows promise for metabolic diseases; the selective MGAT2 inhibitor BMS-963272 decreased inflammation and liver fibrosis in NASH models while increasing GLP-1 and reducing body weight in human subjects, without gastrointestinal tolerability issues 3. Recent evidence suggests elevated MGAT2 is associated with increased glioblastoma risk, potentially through immune-related macrophage pathways 7.