(UroToday.com) Given the recent large efforts to molecularly subclassify bladder cancer, there has been a growing emphasis to ensure external validation and appropriate classification. Researchers from Lund University, Sweden, used bioinformatics tools including rule-based and centroid based algorithms in an attempt to identify methods that can reproducibly classify a newly profiled bladder tumor samples in a manner that is independent of preprocessing, sample purity, and mRNA assay technology.