Reply to Eliezer M. Van Allen, Levi A. Garraway and Jonathan E. Rosenberg's Letter to the Editor re: Floris H. Groenendijk, Jeroen de Jong, Elisabeth E. Fransen van de Putte, et al. ERBB2 Mutations Characterize a Subgroup of Muscle-invasive Bladder Cancers with Excellent Response to Neoadjuvant Chemotherapy. Eur Urol. In press. http://dx.doi.org/10.1016/j.eururo.2015.01.014.