The Gardner lab studies fundamental mechanisms of immune tolerance -- how the immune system learns to distinguish self from non-self -- and how this understanding can be applied in the context of autoimmunity, transplantation, maternal-fetal tolerance, and cancer immunology. We have a particular focus on the biology and function of a unique group of cells expressing the Autoimmune Regulator (Aire) gene. Previously the lab identified extra-Thymic Aire-expressing Cells (eTACs), a novel population that plays significant roles in immune homeostasis and immune tolerance. We have since described the fundamental biology and identity of eTACs, as well as defined potential roles for these populations in autoimmune diabetes and in maternal-fetal tolerance. We utilize multimodal approaches from transgenic engineering to single-cell multiomics to understand the biology and immunology of these unique populations, and more broadly of immune tolerance mechanisms. The Gardner lab also works closely with the UCSF Transplant community and with the VIable Tissue Acquisition Lab (VITAL) Core, which Dr. Gardner established and directs, to advance groundbreaking research in human immunology and human biology. We work collaboratively with a range of investigators locally and nationally in these efforts.