MMP9 and urinary bladder carcinoma: Increasing evidence is showing that various molecular markers, such as p53 [12,13,14,15,16,17,18], p16 [19,20], epidermal growth factor receptor (EGFR) [21,22], human epidermal growth factor receptor-2 (Her-2) [21,22,23], nuclear factor-kappa B (NFκB) [23,24,25], E-cadherin [25], matrix metalloproteinase-9 (MMP9) [26], meiotic recombination 11 homolog (MRE11) [27,28,29], and programmed death-1 ligand (PD-L1) [30], may help predict the outcome of bladder cancer.