CHST10 (carbohydrate sulfotransferase 10) catalyzes sulfate transfer from PAPS to terminal glucuronic acid residues, playing dual roles in neural glycosylation and steroid hormone metabolism. In the nervous system, CHST10 synthesizes the HNK-1 carbohydrate epitope on neural recognition molecules, mediating cell-cell interactions essential for synaptic plasticity and ontogenetic development 1. CHST10 also sulfates the laminin-binding domain of α-dystroglycan, regulating extracellular matrix interactions and defining glycoprotein chain length 2. Beyond neural function, CHST10 down-regulates steroid hormones by sulfating glucuronidated estrogens and androgens, with preference for 3-hydroxyl modification over 17-hydroxyl positions 3. In vivo, Chst10-deficient mice exhibit subfertility and elevated serum estrogen, confirming hormone regulatory capacity 3. CHST10 expression is transcriptionally induced by RARγ activation in melanoma cells, suppressing invasiveness through HNK-1-mediated cell adhesion changes 4. Recent evidence indicates CHST10 upregulation may represent a compensatory response to α-dystroglycan glycosylation defects in dystroglycanopathies 2. In reproduction, mating induces CHST10 activity in oviductal mucosa, generating HNK-1 glycoproteins potentially involved in sperm selection 5. CHST10 is hypermethylated in colorectal cancer, with demethylating agents restoring expression 6.