Our prospective cohort study had indicated that maternal universal screening for congenital CMV infection based on serological tests—including CMV IgG, IgG avidity index, and CMV IgM—in low-risk pregnant women (i.e., pregnant women who were not referred because of positive results for CMV IgM) overlooked a number of congenitally infected newborns, because a larger number of congenital CMV infections were caused by maternal non-primary than by primary CMV infection [14]. The gene discussed is CD40LG; the disease is cytomegalovirus infection.