A Science Immunology study shows axolotls can fully regenerate a complex thymus within roughly 35 days, with functional integration after transplantation in follow‑up assays. More than 60% of juvenile animals regenerated a complete thymus within the timeframe, and transplanted regenerated organs integrated and supported host immunity. Complementing vertebrate organ regeneration, a Nature paper reports an apple snail species that regrows an entire eye in ~30 days with human‑like structural features. Both studies map developmental pathways and cell types mobilized during complete organ reconstruction, offering comparative models for regenerative medicine. Clarification: The thymus is essential for T‑cell development; regeneration of a functional thymus implies restoration of adaptive immune competence in the model organism.