On June 11th, 2026, the PKD community lost a friend, advocate, and scientific pioneer with the passing of Dr. James Calvet, Professor Emeritus of the University of Kansas Medical Center.
Jim entered the world of PKD science after a fortuitous meeting with Dr. Jared Grantham, who intrigued Jim with the neoplastic phenotype of the cysts in PKD kidneys, convincing him that he could apply his expertise in RNA biology to the study of PKD. This led to Jim’s first PKD publication in 1987 detailing the elevated expression of a proto-oncogene in a mouse model of ARPKD, ushering the discipline of molecular biology into the PKD research field, and beginning what became a very productive scientific collaboration.
Jim quickly came into his own in the field, publishing numerous papers and reviews that are still relevant today. Some of his more significant contributions (as identified by some of his closest colleagues) include a 1994 review in which Jim postulated that cysts may be locked in an arrested state of differentiation, a 2006 paper utilizing an embryonic kidney culture method (an early technique in the PKD field revitalized by his long-time research assistant and lab manager, Brenda Magenheimer) that persists as an important assay in use today, and several papers on the PKD1 promoter in the early 2000s that presaged current interest in therapeutic mechanisms to increase expression of the PKD1 gene. In 1998, Jim’s lab was the first to show that the polycystin-1 protein can function as a G protein coupled receptor, and in 2004 demonstrated that calcium restriction drives cAMP-mediated cell proliferation in cystic cells.
In addition to his seminal observations, Jim co-authored manuscripts w/ countless others in the field, and served as a graduate advisor and scientific mentor to numerous trainees and young faculty members (many of whom continue to be active in PKD research). He shared reagents, knowledge, and expertise with all. He was also instrumental in the founding of the University of Kansas Medical Center Jared Grantham Kidney Institute, which is internationally recognized for excellence in kidney biology (particularly in the area of PKD research), and served as Director of the Kansas PKD Research and Translational Core Center for 17 years. Jim’s many and diverse contributions were recognized with the 2011 Lillian Jean Kaplan International PKD Prize (awarded by the International Society of Nephrology and the PKD Foundation) for excellence and leadership in clinical or basic research in polycystic kidney disease.
Above all else, Jim was a valuable and respected mentor, colleague, and friend to all. He will be deeply missed within the PKD community.