The techniques of DNA microarrays, protein arrays, and tissue microarrays complement one another and in the future the combination of these methods will possibly enable the detection of genes specific for bladder cancer. The SELDI technology (surface-enhanced laser desorption/ionization) will then be used to prove if the genes are translated into proteins and if those proteins have a relevant effect on the development and progression of the cancer disease. The consequence is the facilitation of the development of prognostic markers for this disease entity, which can then be easily tested in a large study population by tissue microarray. Beyond the gain of new insights into the biological understanding of the development and progression of bladder cancer, these techniques will hopefully enable the design of new therapeutic concepts, which apply to the individual biology of the tumor.