MGAT5 and cancer: Knockout (KO) mice of another GlcNAc-branching enzyme—GnT-IVa—exhibited a type 2 diabetes-like phenotype because of the impaired function of glucose transporter 2 in pancreatic β-cells16.The β1,6-GlcNAc branch synthesized by GnT-V is involved in cancer development and malignancy as tumor growth and metastasis were greatly inhibited in GnT-V-KO mice17.