The initial concept of this special issue was to invite a duo of experts for each chapter to discuss specific aspects of the mechanisms underlying regenerative processes. In some cases, this invitation came at the right time and two colleagues mutually agreed to join their efforts and deliver their views on a particular topic, within this largely multidisciplinary field that regeneration covers. In other cases, this dialectic pairing could not materialize and close collaborators joined to help write some chapters. In all cases, all contributors went far beyond their favorite model (plants, hydra, planarians, fly, sea cucumber, newt, zebrafish, mammals) to discuss some of the most recent findings and strategies in their field, with a transversal view. As a result, this special issue offers both novel concepts and stimulating ideas on the various mechanisms at work during regeneration.