A study published in Nature elucidates the molecular mechanisms by which axolotl limb cells retain positional memory after amputation, guiding accurate regeneration. Researchers identified key signals regulating Sonic hedgehog (Shh) expression in posterior limb cells and a feedback loop involving fibroblast growth factor 8 (FGF8) and Shh from anterior to posterior domains. These findings explain how adult cells encode spatial identity to reconstruct appropriate limb structures. Insights into this regeneration blueprint may benefit regenerative medicine and tissue engineering.