KLF4 and urinary bladder cancer: KLF4 is a member of the KLF-like factor subfamily of zinc finger proteins, which was recently reported to have a tumor suppressive role in a number of human cancers including bladder cancer, gastric cancer and pancreatic cancer (Ohnishi et al., 2003; Wei et al., 2005; Wei et al., 2008; He et al., 2015).