IFNB1 and Axenfeld-Rieger syndrome: In the present studies, we tested whether genetically engineered L. reuteri releasing IFN-β (LR-IFN-β) is an effective radiation protector and mitigator for intestinal crypt stem cells and if this therapeutic drug increases mouse survival after exposure to irradiation doses that cause gastrointestinal acute radiation syndrome (GI-ARS).