FILE - Melissa Mattola-Kiatos, RN, nursing practice specialist, removes the pig kidney from its box to prepare for transplantation at Massachusetts General Hospital, March 16, 2024, in Boston. Richard “Rick” Slayman, the first recipient of a genetically modified pig kidney transplant, has died nearly two months after he underwent the procedure, his family and the hospital that performed the surgery said Saturday, May 11. (Massachusetts General Hospital via AP, File)