In Japan, the revised Organ Transplant Law has greatly increased the number of pancreas transplants from brain-dead donors, and 437 PTx were performed in Japan between 2000 and 2019.6–8 Simultaneous pancreas–kidney transplantation (SPK) could eliminate both insulin injections and maintenance dialysis and also improve life expectancy in T1DM patients with kidney failure.9 Since 2021, islet transplantation has been reimbursed by National Health Insurance in Japan, which should enable more T1DM patients to be offered the option of transplantation. This evidence concerns the gene INS and kidney failure.