In this study, about 3.0% of test results were IgG+/IgM+ (2.3%), IgG‐/IgM+ (0.1%), or IgG+/IgM grey zone (0.6%), indicating subjects requiring further laboratory tests to distinguish primary CMV infection from past CMV infection/reactivation.4 This evidence concerns the gene CD40LG and cytomegalovirus infection.