A research team led by Wei Wang has demonstrated that activating the Aldh1a2 gene involved in vitamin A metabolism reinitiates regenerative capacity for ear tissue in mice. This evolutionary reactivation of a dormant genetic switch, detailed in Science, provides critical insights into differences among mammals in healing ability. The study employed single-cell RNA sequencing and spatial transcriptomics, revealing fibroblast signaling pathways underpinning regeneration. This work heralds new possibilities for regenerative medicine approaches aimed at restoring complex tissue structures in humans.