CD40LG and cytomegalovirus infection: To be noted, it is often to observe the coexistence of CMV infection with the EBV (Epstein–Barr Virus (EBV) infection, and published reports showed the presence of cross-reactivity of EBV-specific IgM antibodies with CMV antigens, indicating that the EBV infection should be a crucial confounding factor of CMV-pp65/IE-1 and QuantiFERON-CMV tests.[36] Unfortunately, none of the included studies further explored the potential influence of EBV coinfection with CMV on the predictive efficacy.