We mourn the loss of Dr. Mario Amzel, a longtime faculty member who recently stepped down after 15 years as department Director. Mario transformed the Department of Biophysics and Biophysical Chemistry by hiring eight faculty members, broadening its scope to encompass new areas of biophysics and adding new enabling technologies. He was a gifted teacher and devoted mentor to his large number of trainees, who flourished under his guidance. His scientific legacy, beginning with his work on determining the first structure of an antibody in the 1970s, has had a major impact on multiple fields. Mario was also a generous colleague and welcoming host who opened his doors to the entire department each New Year’s eve. He will be deeply missed.