It is with deep sadness that we announce the passing of our dear colleague, John de Groot, who was an integral part of our research group for over 13 years. John’s contributions to the field of inner ear research were invaluable, drawing on a lifetime of expertise. In 1989, he earned his PhD for his groundbreaking work on the cell biological aspects of gentamicin cochleotoxicity. Throughout his entire career, John remained dedicated to the study of the inner ear, beginning his work in Utrecht before joining us in Leiden. He left us far too soon. John was not only a walking encyclopedia on the inner ear but also a generous mentor and a kind friend. His passion for science was matched by his warmth and humility, and he will be deeply missed by all who had the privilege to work with him. John’s legacy will continue to inspire us in the years to come as we carry forward the work he cared about so deeply.