ST6GAL1 and urinary bladder neoplasm: In contrast, invasive bladder tumors were characterized by a decreased ST6GAL1 protein staining (Figures 2B-D): 69.2% (n = 45/65) of all analyzed tumors showed an ST6GAL1 protein staining of IRS ≤ 4 and 25.6% (16/65) exhibited an almost complete loss (IRS = 0) of ST6GAL1 protein (Figure 2G).