CSGALNACT2 is a Golgi-resident glycosyltransferase that catalyzes the transfer of N-acetylgalactosamine (GalNAc) to glucuronic acid, playing a critical role in chondroitin and dermatan sulfate proteoglycan biosynthesis 1. The enzyme is essential for initiating the first GalNAc addition to the core tetrasaccharide linker and for chain elongation during glycosaminoglycan synthesis. In developmental contexts, CSGALNACT2 redundantly functions with CSGALNACT1A; double mutants (csgalnact1a-/-;csgalnact2-/-) show significantly enhanced craniofacial defects compared to single mutants, indicating cooperative roles in craniofacial development 1. Beyond development, CSGALNACT2 acts as a tumor suppressor in ovarian cancer: its expression is downregulated in malignant tissues, and restoration inhibits cancer cell migration and invasion via DUSP1-mediated suppression of MAPK/ERK signaling 2. CSGALNACT2 exhibits prognostic value and correlates with immune cell infiltration patterns in ovarian cancer 2. Additionally, genetic studies identify CSGALNACT2 as a causal risk factor for Hirschsprung disease 3 and vitiligo 4, suggesting pleiotropic roles in developmental and autoimmune pathophysiology. The gene's expression is modulated by exogenous chondroitin sulfates 5, indicating potential feedback regulation of GAG biosynthesis.