To investigate whether inhibition of FUT1 or FUT2 has functional consequences in breast cancer, lentiviral-based short hairpin RNA (shRNA) was employed to establish stable cell lines with silenced expression of FUT1 (shFUT1) or FUT2 (shFUT2) in T47D cells, which expressed significantly more FUT2 than FUT1, and MCF7 cells, which expressed high FUT1 but negligible FUT2. This evidence concerns the gene FUT1 and breast carcinoma.