The function of Ensembl gene identifier ENSG00000064225 (ST3GAL6, ST3 beta-galactoside alpha-2,3-sialyltransferase 6) is as follows. Transfers the sialyl residue from CMP-N-acetyl-beta- neuraminate to the terminal galactose residue on sugar chains of glycoproteins and glycolipids (PubMed:10206952, PubMed:26692484). Its alpha-2,3-sialyltransferase activity is specific toward type II glycan chains (Galbeta1-4GlcNAc) on glycoproteins and glycolipids such as neolactosides nLc4Cer and nLc6Cer, whose sialyl-products serve as precursors for the Lewis X antigen (PubMed:10206952, PubMed:26692484). Critically involved in the synthesis of functional selectin ligands needed for neutrophil recruitment during inflammation and lymphocyte homing to the lymph nodes (By similarity). {ECO:0000250|UniProtKB:Q8VIB3, ECO:0000269|PubMed:10206952, ECO:0000269|PubMed:26692484}.