B4GALNT2 and colonic neoplasm: The Sda blood group carbohydrate structure, GalNAcβ1,4(NeuAcα2,3)Galβ1,4GlcNAc-R, and β1,4-GalNAc transferase (β1,4-GalNAcT) II, which is responsible for Sda synthesis gene expression, are abundantly expressed in the normal gastrointestinal mucosa, while their expression levels are markedly decreased in gastric and colonic cancers.