2-DE gel images showing protein expression in bladder tissues from normal human, NMIBC and MIBC samples. The protein samples were loaded onto nonlinear IPG strips (pH 3-10, 17 cm) in an IEF cell and then separated by 12% SDS-PAGE. The protein spots were visualized by silver staining. The numbers are the spot numbers of detected proteins and arrows indicate the differentially expressed proteins in bladder cancer tissues compared with controls. Representative images from six independent experiments.