Recent advancements in xenotransplantation have overcome hyperacute rejection through genetic modifications in pigs, such as alpha-gal knockout. However, new research presented by Valentin Goutaudier at the European Society for Organ Transplantation congress reveals that human recipients still mount subtler, delayed immune responses to pig organs. Using molecular techniques including spatial transcriptomics and imaging, signs of inflammation and immune activation were detected in pig-to-human kidney transplant patients, suggesting the need for additional inhibitor drugs to manage rejection. This insight underscores ongoing challenges in long-term xenotransplant viability despite FDA approval of initial trials.