SMAD2 and urinary bladder cancer: The expression levels of GP73, TGF‐β1 and Smad2 in bladder cancer tissue samples were significantly higher than those in adjacent and normal bladder tissue samples (61.8% versus 10.8% versus 3.8%, 72.5% versus 19.6% versus 7.5% and 65.7% versus 15.7% versus 6.6%, respectively) (all P < 0.05) (Table 4).