Abstract: This document relates to methods and materials for assessing radiation exposure. For example, methods and materials that can be used to determine whether a mammal (e.g., a human) has been exposed to radiation and/or whether a mammal (e.g., a human) is at risk of developing one or more radiation injuries (e.g., cutaneous radiation injury (CRI) and/or acute radiation syndrome (ARS)) following radiation exposure (e.g., radiation therapy) are provided.