Figure 3
From: Tumour-associated carbohydrate antigens in breast cancer
Biosynthesis of Lewis antigens. Lewis antigens derive from the substitution of type 1 (Galβ1-3GlcNAc) or type 2 (Galβ1-4GlcNAc) disaccharide sequences by fucose and sialic acid residues. Name of the antigen is indicated next to the glycan structure. Names of the main enzymes involved in the biosynthetic pathways are indicated in italics. Arrows, antigens and enzymes altered in breast cancers.