Researchers report that axolotls can fully regenerate the thymus, rebuilding the complex organ and restoring function after complete removal, according to a Science Immunology paper. The team observed early bud formation within seven days and complete regeneration in a majority of juveniles by 35 days, with regenerated organs integrating successfully upon transplantation into other animals. Functional assays demonstrated that regenerated thymuses produced T cells and reconstituted immune architecture, overturning assumptions that thymic loss is irreversible in vertebrates. The study names key cellular processes and regenerative timelines that could inform mammalian thymic‑repair strategies. Regenerative‑medicine researchers and immunologists should examine conserved signals and extracellular matrix cues identified in axolotls to inform bioengineering or small‑molecule approaches aimed at restoring thymic function in humans. Source: Science Immunology.