"In recent years, new evidence has been gathered about how the immune system recognizes alloantigens and how this can lead to kidney transplant rejection. Examples of these insights include: - importance of HLA beyond the A/B/DR loci (use of high-resolution genotyping, HLA-DQ locus) - donor-recipient mismatches in non-HLA loci (increased risk of allograft dysfunction, formation of non-HLA antibodies) - beyond the adaptive immune system: innate allorecognition (missing self, SIRP-alpha mismatches) These advances have the potential to improve pretransplant risk assessment and optimize donor organ allocation in order to minimize risk, but it is currently unclear how this could be implemented to improve outcomes. This session aims to provide an overview of the current body of evidence for these new mechanisms of allorecognition, whether and how these should have an impact on how donor organs are allocated, and what the impact on current practices would be.