Radiation Injury Description: Granexin® gel is an easy-to-use, stable, topically applied gel containing the short regulatory peptide (aCT1) that possesses potent anti-inflammatory properties and accelerates cutaneous wound healing. FirstString Research proposes to further validate the efficacy, safety, and therapeutic potential of Granexin in the mitigation and treatment of CRI. The proposed development efforts will support NDA submission to the FDA for Granexin as a medical countermeasure (MCM) for CRI under the Animal Rule.