Abstract: This document relates to methods and materials involved in identifying and/or treating mammals having a CMV infection. For example, methods and materials for assessing a mammal having a CMV infection (e.g., a CMV seronegative human who received CMV seropositive donor transplant tissue) to determine if the mammal is likely to control the CMV infection or to determine if the mammal is unlikely to control the CMV infection are provided. Methods and materials for treating a mammal having a CMV infection (e.g., a CMV seronegative human who received CMV seropositive donor transplant tissue) that was either identified as being likely to control the CMV infection or identified as being unlikely to control the CMV infection also are provided.