Christiaan De Jong, MD, Erasmus University Medical Center, Rotterdam, The Netherlands, discusses the findings of a study which performed transcriptome sequencing on samples from patients with T1 high-grade bladder cancer who had been treated with Bacillus Calmette-Guérin (BCG) with the goal of identifying molecular predictors of BCG failure. Three new molecular subtypes were identified by mRNA consensus clustering: BCG1, BCG2 and BCG3. Patients with BCG3 tumors had a worse progression-free survival (PFS) and high-grade recurrence-free survival in comparison to patients with BCG1 and BCG2 tumors. Patients with BCG1 tumors demonstrated a favorable PFS. It was also found that 67% of post-BCG tumor recurrences were BCG3 tumors. Overall, Dr De Jong reports that these insights can be used to improve clinical risk stratification of patients to receive BCG therapy versus early radical cystectomy, and talks on recent research which aims to validate this risk stratification model. This interview took place at the virtual European Association of Urology (EAU) Virtual Meeting 2021.