This study revealed the following key insights into GCNT2 expression and its relationship with bladder cancer malignancy: (1) GCNT2 expression was inversely correlated with bladder cancer aggressiveness, (2) GCNT2 expression affected the NK cell-mediated immunity in bladder cancer cells, and (3) I-branching glycans regulated by GCNT2 impacted the NK cell functions. The gene discussed is GCNT2; the disease is urinary bladder cancer.