Changes in gene expression and enzymatic activity of several glycosyltransferases have been reported in cancer cells and could affect the main sialyltransferases (ST) involved in the addition of α2,6-SA and α2,3-SA: ST6Gal1, ST3Gal3, ST3Gal4 and ST3Gal6, and the N-acetylgalactosaminyltransferases B4GALNT involved in the transfer of β1-4 GalNAc50. This evidence concerns the gene ST3GAL3 and cancer.