Developed to cull: How a master control gene of development turned into a regulator of innate immune homeostasis

A striking novel role for the Caudal "master control" gene of development in the regulation of innate immune functions in insects has emerged. A recent study now adds further insight into the function of this homeobox gene in the maintenance of the immune homeostasis that is required to preserve the normal commensal community within the Drosophila gut. These results point to a possible more widespread co-option of developmental regulatory genes during evolution to add tissue- and/or organ-specific regulatory plasticity to innate immune systems.