Reply to Chris R. Cardwell, Samy Suissa and Liam J. Murray's letter to the editor re: Helene Hartvedt Grytli, Morten Wang Fagerland, Sophie D. Fosså, Kristin Austlid Taskén. Association between use of β-blockers and prostate cancer-specific survival: a cohort study of 3561 prostate cancer patients with high-risk or metastatic disease. Eur Urol. In press. http://dx.doi.org/10.1016/j.eururo.2013.01.007