Because FUCA1 catalyzes the hydrolytic cleavage of the terminal alpha-L-fucose residue in glycoproteins and glycolipids that are associated with the transformation to a malignant phenotype [1], we quantified the levels of fucosylated Lewis-x antigens in breast tumor tissues with high or low FUCA1 expression using IHC H-score staining assays, as described in the Materials and Methods section (Figure 2A, 2B and 2C). This evidence concerns the gene FUT4 and breast neoplasm.