The aim of this Special Issue is to highlight the close functional and highly conserved link between innate immunity, homeostasis maintenance, inflammation, tissue remodeling and regeneration. In the last few decades, the rules on the use of vertebrates in biological trials have become increasingly stringent and, in this context, invertebrates are used as complementary animal models, considering that they are cost-effective and easy to handle. Here, original articles and reviews on cells and mechanisms involved in immunity, in the regulation of inflammation and tissue regeneration processes, focused on invertebrate models, are gathered.

Considerable efforts have been made to shed light on phylogenetic distribution and developmental patterns of wound healing and regeneration mechanisms, as well as on their ecological value. Comparative research on regeneration and its relationship to the immune system has been a long-standing concern. Most likely, the capability to regenerate whole organs and body parts concurs with the origin of multicellularity and many invertebrate models have relevant regeneration abilities, unlike in vertebrates, in which this skill is significantly reduced.